DATA ROUTING IN COMMUNICATIONS SYSTEMS
20250330421 ยท 2025-10-23
Inventors
Cpc classification
Y02B10/20
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
Y02E10/50
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
Y02E10/47
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
F24S25/33
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F24S2025/6008
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F24S2025/803
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F24S25/70
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
H04L12/4633
ELECTRICITY
F24S25/61
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F24S2025/807
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
Y02B10/10
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
H04W8/082
ELECTRICITY
H04L45/50
ELECTRICITY
International classification
H04L45/00
ELECTRICITY
Abstract
A method, a system, and a computer program product for data routing in communications systems. A data packet is received and an internet protocol (IP) address of the data packet is determined based on the source of the data packet. A forwarding route for transmission of the data packet is determined. The forwarding route is selected from a specific IP route for a content offload network interface or a default route for a mobile network operator packet data network gateway. The data packet is transmitted based on the determined forwarding route.
Claims
1. A computer-implemented method, comprising: receiving a data packet; determining, using at least a portion of data contained in the received data packet, an internet protocol (IP) address for forwarding the received data packet; determining, based on the determined IP address for the data packet, a forwarding route for transmission of the data packet, wherein the forwarding route is selected from a specific IP route for a content offload network interface or a default route for a mobile network operator (MNO) packet data network gateway (PGW); and transmitting the data packet based on the determined forwarding route.
2. The method of claim 1, further comprising identifying a predetermined network address translation (NAT) range of addresses corresponding to the portion of data contained in the received data packet.
3. The method of claim 1, further comprising determining whether the data packet arrived on an MNO facing interface, determining whether the data packet was transmitted from the MNO's PGW, and determining the forwarding route only if the data packet arrived on the MNO facing interface and the data packet was transmitted from the MNO's PGW.
4. The method of claim 1, further comprising: identifying whether the data packet is a General Packet Radio Service tunneling protocol (GTP) packet or an IP packet based on a protocol header.
5. The method of claim 1, wherein the data packet is a GTP packet received from a mobile network operator's evolved packet core, and wherein the forwarding route is to an eNodeB associated with a user equipment session identified by a tunnel endpoint identifier (TEID).
6. The method of claim 1, wherein the data packet is a GTP packet received from an eNodeB, and further comprising: de-encapsulating the GTP packet to extract an encapsulated IP packet; determining whether the destination address of the encapsulated IP packet matches a known content route; and performing source network address translation of the IP packet prior to transmission along the known content route.
7. The method of claim 1, wherein the forwarding route is determined using an offload routing table stored in a memory of the system.
8. The method of claim 1, further comprising: allocating a source network address translation (NAT) address from a predetermined address range upon determining that the data packet corresponds to a new user session.
9. A system comprising: at least one data processor; a memory storing instructions which, when executed by the at least one data processor, causes the at least one data processor to perform operations comprising: receiving a data packet; determining, using at least a portion of data contained in the received data packet, an internet protocol (IP) address for forwarding the received data packet; determining, based on the determined IP address for the data packet, a forwarding route for transmission of the data packet, wherein the forwarding route is selected from a specific IP route for a content offload network interface or a default route for a mobile network operator (MNO) packet data network gateway (PGW); and transmitting the data packet based on the determined forwarding route.
10. The system of claim 9, wherein the memory storing instructions cause the at least one data processor to perform operations further comprising identifying a predetermined network address translation (NAT) range of addresses corresponding to the portion of data contained in the received data packet.
11. The system of claim 9, wherein the memory storing instructions cause the at least one data processor to perform operations further comprising determining whether the data packet arrived on an MNO facing interface and determining whether the data packet was transmitted from the MNO's PGW, and determining the forwarding route only if the data packet arrived on the MNO facing interface and the data packet was transmitted from the MNO's PGW.
12. The system of claim 9, wherein the system is located proximate to a base station operated by the mobile network operator.
13. The system of claim 9, further comprising a port configured to receive GTP packets from an eNodeB and a second port configured to transmit IP packets to a local content provider network.
14. The system of claim 9, wherein the memory further stores: a TEID-to-session mapping table and a NAT translation table, each used to identify user equipment sessions and perform address translations.
15. The system of claim 9, wherein the memory further stores a routing table comprising one or more specific IP routes for known content destinations.
16. A non-transitory computer program product storing instructions, which when executed by at least one data processor of at least one computing system, implement a method comprising: receiving a data packet; determining, using at least a portion of data contained in the received data packet, an internet protocol (IP) address for forwarding the received data packet; determining, based on the determined IP address for the data packet, a forwarding route for transmission of the data packet, wherein the forwarding route is selected from a specific IP route for a content offload network interface or a default route for a mobile network operator (MNO) packet data network gateway (PGW); and transmitting the data packet based on the determined forwarding route.
17. The computer program product of claim 16, wherein the computer program product causes the at least one data processor to perform operations further comprising identifying a predetermined network address translation (NAT) range of addresses corresponding to the portion of data contained in the received data packet.
18. The computer program product of claim 16, wherein the instructions, when executed, further cause the system to perform operations further comprising determining whether the data packet arrived on an MNO facing interface and determining whether the data packet was transmitted from the MNO's PGW, and determining the forwarding route only if the data packet arrived on the MNO facing interface and the data packet was transmitted from the MNO's PGW.
19. The computer program product of claim 16, wherein the instructions, when executed, further cause the system to perform operations further comprising discarding a GTP packet if the associated TEID is not present in a state table.
20. The computer program product of claim 16, wherein the instructions, when executed, further cause the system to perform operations further comprising receiving a packet on a content-facing interface and encapsulating it in a GTP header using a TEID associated with a user session prior to transmitting it to an eNodeB.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The accompanying drawings, which are incorporated in and constitute a part of this specification, show certain aspects of the subject matter disclosed herein and, together with the description, help explain some of the principles associated with the disclosed implementations. In the drawings,
[0013]
[0014]
[0015]
[0016]
[0017]
[0018]
[0019]
[0020]
[0021]
[0022]
[0023]
[0024]
[0025]
[0026]
[0027]
[0028]
[0029]
[0030]
DETAILED DESCRIPTION
[0031] To address the deficiencies of currently available solutions, one or more implementations of the current subject matter provide methods, systems, and devices for offloading traffic in a wireless communication system. The following is a description of an exemplary wireless communication system, e.g., a long term evolution communication system.
[0032]
[0033] As shown in
[0034]
[0035] Communication between the user equipment 102 and the eNodeB 204 occurs via an air interface 208 (also known as LTE-Uu interface). As shown in
[0036] The air interface 208 uses various protocols, which include a radio resource control (RRC) for signaling between the user equipment 102 and eNodeB 204 and non-access stratum (NAS) for signaling between the user equipment 102 and MME (as shown in
[0037] Multiple eNodeBs 204 can be interconnected with one another using an X2 interface (e.g., X2 interface 210 connecting ENB2 204b and ENB3 204c). The X2 interface can be established between two eNodeBs in order to provide an exchange of signals, which can include load- or interference-related information as well as handover-related information. The eNodeBs 204 communicate with the evolved packet core 106 via an S1 interface 206 (a, b, c). The S1 interface 206 can be split into two interfaces: one for the control plane (i.e., S1-MME interface 302) and the other for the user plane (i.e., S1-U interface).
[0038] The EPC 106 establishes and enforces Quality of Service (QOS) for user services and allows user equipment 102 to maintain a consistent internet protocol (IP) address while moving. It should be noted that each node in the network 100 has its own IP address. The EPC 106 is designed to interwork with legacy wireless networks. The EPC 106 is also designed to separate control plane (i.e., signaling) and user plane (i.e., traffic) in the core network architecture, which allows more flexibility in implementation, and independent scalability of the control and user data functions.
[0039] The EPC 106 architecture is dedicated to packet data and is shown in more detail in
[0040] The SGW 304 functions as an IP packet data router and is the user equipment's bearer path anchor in the EPC 106. Thus, as the user equipment moves from one eNodeB 204 to another during mobility operations, the SGW 304 remains the same and the bearer path towards the EUTRAN 104 is switched to talk to the new eNodeB 204 serving the user equipment 102. If the user equipment 102 moves to the domain of another SGW 304, the MME 308 will transfer all of the user equipment's bearer paths to the new SGW. The SGW 304 establishes bearer paths for the user equipment to one or more PGWs 312. If downstream data are received for an idle user equipment, the SGW 304 buffers the downstream packets and requests the MME 308 to locate and reestablish the bearer paths to and through the EUTRAN 104.
[0041] The PGW 312 is the gateway between the EPC 106 (and the user equipment 102 and the EUTRAN 104) and PDN 108 (shown in
[0042] The MME 308 manages user equipment 102 within the EPC 106, including managing subscriber authentication, maintaining a context for authenticated user equipment 102, establishing data bearer paths in the network for user traffic, and keeping track of the location of idle mobiles that have not detached from the network. For idle user equipment 102 that needs to be reconnected to the access network to receive downstream data, the MME 308 initiates paging to locate the user equipment and re-establishes the bearer paths to and through the EUTRAN 104. MME 308 for a particular user equipment 102 is selected by the eNodeB 204 from which the user equipment 102 initiates system access. The MME 308 is typically part of a collection of MMEs in the EPC 106 for the purposes of load sharing and redundancy. In the establishment of the user's data bearer paths, the MME 308 is responsible for selecting the PGW 312 and the SGW 304, which will make up the ends of the data path through the EPC 106.
[0043] The PCRF 314 is responsible for policy control decision-making, as well as for controlling the flow-based charging functionalities in the policy control enforcement function (PCEF), which resides in the PGW 312. The PCRF 314 provides the QoS authorization (Qos class identifier (QCI) and bit rates) that decides how a certain data flow will be treated in the PCEF and ensures that this is in accordance with the user's subscription profile.
[0044] As stated above, the IP services or servers are provided by the PDN 108 (as shown in
[0045] One of the primary functions of the eNodeB 204 is radio resource management, which includes scheduling of both uplink and downlink air interface resources for user equipment 102, control of bearer resources, and admission control. The eNodeB 204, as an agent for the EPC 106, is responsible for the transfer of paging messages that are used to locate mobiles when they are idle. The eNodeB 204 also communicates common control channel information over the air, header compression, encryption and decryption of the user data sent over the air, and establishing handover reporting and triggering criteria. As stated above, the eNodeB 204 can collaborate with other eNodeB 204 over the X2 interface for the purposes of handover and interference management. The eNodeBs 204 communicate with the EPC's MME via the S1-MME interface and to the SGW with the S1-U interface. Further, the eNodeB 204 exchanges user data with the SGW over the S1-U interface. The eNodeB 204 and the EPC 106 have a many-to-many relationship to support load sharing and redundancy among MMEs and SGWs. The eNodeB 204 selects an MME from a group of MMEs so the load can be shared by multiple MMEs to avoid congestion.
[0046] The system 100, as shown in
[0047]
[0048] Using system 340, user equipment can transmit a request for data through the data networks 354, 356 and the core network to one or more servers that may be located in the internet 342. In response to the request, the servers can transmit the requested data to the user equipment. The process is typically high-resource consuming, compute intensive, prone to data/path loss, errors, can suffer from poor quality of service, can have higher costs of data transmission/reception, etc.
[0049] In some implementations, the current subject matter provides backhaul and content routing/offloading using a local IP access appliance system (LIPA). This system can be placed at several and/or any location within a communications network (e.g., such as a network described above in reference to
[0050]
[0051]
[0052] The LIPA appliance 406 can provide content backhaul and content offloading based on an identification of a source, type, and/or any other information associated with a data transmission (e.g., data packet(s)) received by the LIPA appliance 406 and/or based on any other parameters. Once the information associated with the data transmission is determined, the LIPA appliance 406 can execute an appropriate routing decision for the purposes of routing the received data packet(s). In some implementations, the LIPA appliance 406 can also incorporate one or more functionalities of a serving gateway (SGW).
[0053] The appliance 406 can be any computing device, including hardware, software, and/or any combination thereof for performing functions described herein. The appliance 406 can also have various communications capabilities and can be communicatively coupled to the data network 404 as well as host peering appliance 408, as shown in
[0054]
[0055] In some implementations, the port 802 (also referred to as MNO facing port) can be configured with IP addressing appropriate to reach the mobile network operator's EPC components 418 and/or any eNodeBs 402 that the appliance 406 can be communicatively coupled with (as shown in
[0056] In some implementations, the port 804 (also referred to as content facing port) can be configured with appropriate IP addresses to communicate with local peering exchange network (e.g., with host peering system 408, as shown in
[0057] In some implementations, the source NAT components 808 can be provided with a user equipment source NAT range, which can also be coordinated with the operator of the peering exchange network. In some implementations, each appliance 406 can be assigned a unique user equipment NAT range of addresses, which can be supplied to each content provider that it peers with. Unique source NAT address range can allow content providers to deliver packets intended for each user equipment communicating with the mobile network operator, which avoids confusion as to which mobile network operator components/user equipments should receive the data packets from content providers.
[0058] In some implementations, the NAT features of the source NAT components 808 can include session state based on both user equipment source IP address and GTP TEID assigned to the user equipment/eNodeB session. This information can permit source NAT components 808 to distinguish between various user equipments, content requests, etc.
[0059] As can be understood, the appliance 406 can include various other processing components (e.g., processing components 806), software, hardware, and/or any combination thereof. The appliance 406 can be configured have various communication capabilities and can be communicatively coupled to any component within the communication system (as for example, shown in
[0060]
[0061]
[0062] As shown in
[0063] Upon determination that the received content request should be routed along a default route, the appliance can transmit the content request, via route 604, to the mobile network controlled EPC 418, which can then transmit it to the content provider 422. The content provider 422 can generate a response and transmit it, via route 606, toward the EPC 418, which can then route it to the appliance 406. To ensure that content requests and responses to content requests are routed through the appliance 406, a backhaul GTP session 612 can be established (as shown by Northbound GTP TEID SGW <->PGW Backhaul GTP Session in
[0064]
[0065] Once the requested content is located, the content provider 412a can transmit a response, including the information/data requested in the received request, via route 618, through the data network 410, to the appliance 406. The appliance 406 can the transmit the received responsive information/data to the base station 402c via route 608, as discussed above. In some implementations, the appliance 406 can be directly (and/or indirectly) connected to any interfaced computing and/or communications system using any type of connection, e.g., any type of data network. In some exemplary, non-limiting implementations, the connections can include at least one of the following: one or more links (e.g., physical links, Ethernet links, IP links, physical domain(s) shared by one or more data transmitters/receivers/transceivers, radio waves, waveguides/coaxial connections, optical waves in free space/fiber, electromagnetic wave(s) on metal wire(s), dielectric guide(s), and/or any other connections and/or any combination thereof), one or more switched/hubbed emulated connections, one or more independent point-to-point connections and/or circuits, another one or more networks/data routers (which can be connected to one or more other data networks of same and/or different types), and/or any other type of connections and/or any combinations thereof. While
[0066]
[0067] Upon determination that a GTP packet has arrived on the MNO facing port 802, at 702, a determination can be made whether the GTP packet has been transmitted from mobile network operator's PGW (i.e., MNO PGW 418 as shown in
[0068] If it is determined that the GTP TEID of the GTP packet is not in the state table accessed by the appliance 406, at 730, the GTP packet can be discarded, at 728, and any further forwarding/transmission of the GTP packet can end. Similarly, if, at 704, it is determined that the GTP packet is not from mobile network operator's PGW, and it is not transmitted from mobile network operator's eNodeB, at 706, the GTP packet can also be discarded, at 728, thereby ending further processing of the GTP packet.
[0069] If it is determined that the GTP packet is from mobile network operator's eNodeB, at 706, the source NAT component 808 (as shown in
[0070] If a stored source NAT entry does not exist, the appliance 406 can allocate a source NAT entry to the GTP packet's TEID from a pool of entries, at 710. In some implementations, available entries in the pool can be known to the NAT application software/logic using at least one of the following methods: 1) a static declaration using an explicit configuration; 2) a learned through dynamic routing protocol(s); 3) a learned and/or shared by network-delivered configuration directive(s). In some implementations, a set of addresses including one or more addresses and/or entire address prefixes (e.g., ranges of desired addresses), using which the NAT application code can represent the user equipment's original IP address, can be defined and/or exposed. The address declaration can be used to logically calculate and/or update the NAT table updates on an as-needed basis using the table population processes discussed above.
[0071] Otherwise, if an entry already exists, the GTP packet can be de-encapsulated and a translation of the user equipment's source IP address can be performed by the appliance 406, at 712. Then, after translation, an IP packet can be provided to the host system virtual interface, at 714. In some implementations, a host computer operating system can provide IP routing (e.g., an offload routing table) functions. In this case, the GTP encapsulation and/or de-encapsulation software can exchange IP packets with the host operating system through a system-provided network interface application programming interface and/or other functional network interface emulation mechanism. The host operating can expose to the GTP software one or more such software virtual and/or emulated physical interfaces using which the GTP processing software can both read IP packets from and/or write IP packets to in furtherance of delivering and/or offloading of intended IP packets to desired offload destinations. Additionally, traffic from such offload sources can be received and/or returned to the appropriate user equipment (e.g., via later un-NATing and/or GTP re-encapsulation). In exemplary implementations where there is no provided host operating system IP routing function, and where an external router device is attached to the LIPA appliance, then the interface can become a physical data link interface of various types (e.g., Ethernet, high speed serial, PCI, PCI-E, etc.).
[0072] At 716, an offload routing table can be accessed to determine a route for the IP packet. In some implementations, an IP routing table function can be provided by a host computer operating system. The routing table can be stored in random access memory (ies) and/or any other memory type (e.g., cam, tcam, etc.). The routing table can be populated using at least one of the following methods: 1) entry and/or definition of a static route(s); 2) a routing protocol (e.g., OSPF, BGP, etc.) receives routes from external routers and/or other similar systems and then instructs a host IP routing table, through an API or other mechanism, of the routes it should contain and their associated attributes (e.g., metrics, next-hop interfaces/IP addresses, label imposition, pop, swap, etc.). In some implementations, the IP routing functions can be external from the GTP and/or NAT functions.
[0073] If the route is contained in the offload routing table, at 718, the IP packet can then be forwarded to the indicated next-hop via content facing port 804, at 726.
[0074] If the route is not in the offload routing table, at 718, the IP packet is provided to the GTP/NAT daemon virtual interface, at 720. In some implementations, a host computer operating system can provide IP routing (e.g., an offload routing table) functions. In this case, the GTP encapsulation and/or de-encapsulation software can exchange IP packets with the host operating system using a system-provided network-like interface API and/or other functional network interface emulation mechanism. The host operating can expose one or more such software virtual and/or emulated physical interfaces to the GTP software, with which the GTP software can read IP packets from and/or write IP packets to in furtherance of delivering and/or offloading intended IP packets to desired offload destinations. Further, traffic from such offload sources can be received and/or returned to the appropriate user equipment (e.g., via later un-NATing and GTP re-encapsulation), as discussed above. In exemplary implementations where there is no provided host operating system IP routing function, and where an external router device is attached to the LIPA appliance 406, then this interface can be a physical data link interface (e.g., Ethernet, high speed serial, PCI, PCI-E, etc.). The appliance 406 can then perform a lookup of the source IP address associated with the packet in the user equipment NAT table, translate source address to original user equipment source IP address, and encapsulate it with known GTP TEID and PGW destination, at 722. The NAT processing logic can use a single table, which can associate any, some, and/or all of the user equipment IP address(es) and/or associated Slu and S5/8 GTE TEIDs. Then, the GTP packet is forwarded to determined PGW of the mobile network provider via MNO facing port 802 (as shown in
[0075] If an IP packet is received on the content facing port 804, at 703, the appliance 406 can perform a lookup of a table containing a user equipment source NAT ranges. If the route associated with the received IP packet is not in the user equipment source address table, at 707, the IP packet can be discarded, at 709, and any further processing of the IP packet can be terminated. If the route is in the user equipment source address table, at 707, the appliance 406 can provide the IP packet to the GTP/NAT daemon virtual interface, at 711. At 713, the appliance 406 can then determine whether the packet's destination IP address is allocated to existing TEID translation. If not, the IP packet is discarded, at 709. If it has been allocated, then the appliance 406 can translate NAT-range destination IP address to user equipment destination address, encapsulate it with matching GTP TEID, and set destination GTP IP address to target eNodeB, at 715. At 717, subsequent to the encapsulation, a GTP packet can be forwarded to the determined eNodeB using MNO facing port 802 (as shown in
[0076] In some exemplary implementations, only GTP packets can be sent and/or received using the MNO facing port 802 and only IP packets can be received on the content facing port 804. Further, GTP packets can be exchanged only with eNodeBs and SGWs that were identified by the EPC (MME) 418 (as shown in
[0082]
[0083] Upon determination that a GTP packet has arrived on the MNO facing port 802, at 902, a determination can be made whether the GTP packet has been transmitted from mobile network operator's PGW (i.e., MNO (PGW) 418 as shown in
[0084] If, at 904, it is determined that the GTP packet is not from mobile network operator's PGW, and it is not transmitted from mobile network operator's eNodeB, at 906, the GTP packet can also be discarded, at 912, thereby ending further processing of the GTP packet.
[0085] If it is determined that the GTP packet is from mobile network operator's eNodeB, at 906, a determination can be made whether the encapsulated user equipment IP packet destination IP address is in an offload table, at 914. If so, the GTP packet can be de-encapsulated, at 916. Then, the IP packet can then be forwarded to the indicated next-hop via content facing port 804, at 918. Otherwise, if the packet destination IP address is not in the offload table, at 914, the GTP packet can be forwarded to determined PGW of the mobile network provider via MNO facing port 802 (as shown in
[0086] If an IP packet is received on the content facing port 804, at 901, the appliance 406 can determine whether the content IP packet destination IP address is in UE/SGW session table, at 903. If not, the IP packet can be discarded, at 905, and any further processing of the IP packet can be terminated. If so, the appliance 406 can encapsulate content IP packet with GTP header and associated TEID value for UE destination address, at 907. At 909, subsequent to the encapsulation, a GTP packet can be forwarded to the determined eNodeB using MNO facing port 802 (as shown in
[0087] The following provides a discussion of various ways for offloading and/or routing data using system 400 shown in
Type 1 System
[0088]
[0089] Referring to
[0090] The GTP-U daemon 1003 can include components that can perform GTP encapsulation/de-encapsulation, determine UE TEID and NAT states, and can include an integrated IP routing information base (RIB). The GTP-U daemon 1003 and GTP-C S11 daemon 1005 can be communicatively coupled using a GTP TEID synchronization API interface, which can be used for transmission of data for the purposes of performing encapsulation/de-encapsulation of data packets. The packets 1019 and 1023 can be received, via the interface 1011 and kernel routing table 1009, and processed by the daemon 1003 encapsulation/de-encapsulation components. The control packets 1021 can be received by the daemon 1005 via the interface 1011 and kernel routing table 1009 also. The routing protocol daemon 1007 can push protocol RIB data to the GTP-U daemon 1003's RIB.
[0091] Similar to
[0092] Upon determination that a GTP packet has arrived on the MNO facing interface, at 1002, a determination can be made whether the GTP packet has been transmitted from mobile network operator's PGW. If the GTP packet was transmitted from the mobile network operator's PGW, the system 1000 can access a state table to determine whether GTP TEID associated with the GTP packet is stored in that table, at 1010. In some implementations, the table can include various data structures, which, by way of a non-limiting example, can include at least one of the following: a linked list, an indexed list, an ordered list, a multi-level lookup-abstracted data structure, and/or any other data structures, and/or any combination thereof. Upon receipt of a data packet, the table can be accessed and an appropriate determination as to how the data packet should be processed and/or discarded can be made. By way of a non-limiting example, the table can include one or more of the following exemplary types of data in a row: [unique index] [UE IMSI] [UE GUTI] [EPS bearer ID] [slu TEID] [slu eNb destination IP] [s5/8 TEID] [s5/8 TEID PGW destination IP] [assigned UE PDN IP address]. As can be understood, other data (including more or less than the above listing) can be included in the table. In some implementations, the table can reside within the GTP-U daemon 1003, and/or can be part of the GTP de-encapsulation/encapsulation function block of the GTP-U daemon 1003, as shown in
[0093] If it is determined that the GTP TEID of the GTP packet is not in the state table, at 1010, the GTP packet can be discarded, at 1012, and any further forwarding/transmission of the GTP packet can end. Similarly, if, at 1004, it is determined that the GTP packet is not from mobile network operator's PGW, and it is not transmitted from mobile network operator's eNodeB, at 1006, the GTP packet can also be discarded, at 1012, thereby ending further processing of the GTP packet.
[0094] If it is determined that the GTP packet is from mobile network operator's eNodeB, at 1006, the system 1000 can perform an offload routing table lookup, at 1008. In some implementations, the offload table can include IP routing information (also known as the IP RIB table of the GTP-U daemon process 1003 shown in
[0095] If the route is in the offload routing table, at 1014, a determination can be made as whether there is an existing one-to-one correspondence with a source NAT entry for a particular TEID, at 1016. If not, a source NAT entry for the TEID is allocated from the IP address pool, at 1018. In some implementations, available entries in the pool can be known to the NAT application software/logic using at least one of the following methods: 1) a static declaration using an explicit configuration; 2) a configuration learned through dynamic routing protocol(s); 3) a learned and/or shared by network-delivered configuration directive(s). In some implementations, a set of addresses including one or more addresses and/or entire address prefixes (e.g., ranges of desired addresses), using which the NAT application code can represent the user equipment's original IP address, can be defined and/or exposed. The address declaration can be used to logically calculate and/or update the NAT table updates on an as-needed basis using the table population processes discussed above.
[0096] In some implementations, allocation and/or deallocation of entries in the NAT table can be performed using at least one of the following processes: [0097] programmatic/linear/random/pseudorandom traversal(s), with and/or without consideration of a last-allocated and/or last deallocated pointer and/or counter, with and/or without consideration of a list of configured addresses, and/or any other processes, and/or any combination thereof. Then, the results of the above processes can be compared to a signifier and/or an abstract flag that encodes and/or confers an in use and/or not in use state. In cases where the entire table of available addresses is complete and there are no entries that are free, exception handling logic can be executed, which can include one or more scavenger and/or abort functions. Using these functions, an allocator component can determine if it should re-claim the oldest and/or least-recently-active (i.e., one that has not had a packet match in N-unit of time) and/or other compared metric. In the abort cases, if no entries are free, the allocator component can be configured to return the packet along a normal forwarding path (i.e., towards the current, existing GTP TEID state and known PGW), and thus not offload the packet.
[0098] In some implementations, the IP address pool can be stored in a memory, and/or managed and/or updated by the NAT function block (assuming it was so enabled in the system's configuration). In some exemplary, non-limiting implementations, the NAT table format can include at least the following items: [unique index] [UE IMSI] [UE GUTI] [EPS bearer ID] [UE PDN IP] [UE NAT source IP].
[0099] In some implementations, the allocation process can begin with a determination if the destination IP address in a packet that arrived on the content-facing interface (from a content serving system and/or other IP system etc.) is allocated to an active translation (i.e., whether there is a unique index found when the field UE NAT source IP is searched using the destination address in the received from-content packet). If the unique index (i.e., non-null index value) is returned, then a determination is made whether the EPS bearer ID exists in the GTP state table (which can be part of the operation 1010 shown in
[0100] Referring back to
[0101] If an IP packet is received on the content facing interface, at 1028, the system 1000 can perform a lookup of a table containing a user equipment source NAT ranges, at 1030. If the route associated with the received IP packet is not in the user equipment source address table, at 1032, the IP packet can be discarded, at 1034, and any further processing of the IP packet can be terminated. If the route is in the user equipment source address table, at 1032, the system 1000 can determine whether the packet's destination IP address is allocated to existing TEID translation, at 1036. If not, the IP packet is discarded, at 1034. If it has been allocated, then the system 1000 can translate NAT-range destination IP address to user equipment destination address, encapsulate it with matching GTP TEID, and set destination GTP IP address to target eNodeB, at 1038. At 1040, subsequent to the encapsulation, a GTP packet can be forwarded to the determined eNodeB using MNO facing interface.
Type 2 System
[0102]
[0103] Referring to
[0104] GTP-U daemon 1103 can be configured to provide GTP encapsulation/de-encapsulation functionalities as well as determine UE TEID and NAT states. In some implementations a separate interface (interface 3, as shown in
[0105] The GTP-U daemon 1103 and GTP-C S11 daemon 1105 can be communicatively coupled using a GTP TEID synchronization API interface (similar to
[0106]
[0107] Upon determination that a GTP packet has arrived on the MNO facing interface, at 1102, a determination can be made whether the GTP packet has been transmitted from mobile network operator's PGW. If the GTP packet was transmitted from the mobile network operator's PGW, the system 1100 can access a state table to determine whether GTP TEID associated with the GTP packet is stored in that table, at 1130. If so, the GTP packet can be forwarded to the determined eNodeB associated with the UE TEID using the MNO facing interface, at 1132-1134.
[0108] If it is determined that the GTP TEID of the GTP packet is not in the state table, at 1130, the GTP packet can be discarded, at 1128, and any further forwarding/transmission of the GTP packet can end. Similarly, if, at 1104, it is determined that the GTP packet is not from mobile network operator's PGW, and it is not transmitted from mobile network operator's eNodeB, at 1106, the GTP packet can also be discarded, at 1128, thereby ending further processing of the GTP packet.
[0109] If it is determined that the GTP packet is from mobile network operator's eNodeB, at 1106, the source NAT component can determine whether the GTP TEID corresponds to a source NAT entry, at 1108. If a stored source NAT entry does not exist, the system 1100 can allocate a source NAT entry to the GTP packet's TEID from a pool of entries, at 1110. Otherwise, if an entry already exists, the GTP packet can be de-encapsulated and a translation of the user equipment's source IP address can be performed by the system 1100, at 1112. Then, after translation, an IP packet can be provided to the host system interface, at 1114. At 1116, an offload routing table can be accessed to determine a route for the IP packet. If the route is contained in the offload routing table, at 1118, the IP packet can be forwarded to the indicated next-hop via content facing interface, at 1126.
[0110] If the route is not in the offload routing table, at 1118, the IP packet can be provided to the GTP/NAT daemon interface, at 1120. The system 1100 can then perform a lookup of the source IP address associated with the packet in the user equipment NAT table, translate source address to original user equipment source IP address, and encapsulate it with known GTP TEID and PGW destination, at 1122. Then, the GTP packet can be forwarded to the determined PGW of the mobile network provider via MNO facing interface, at 1124.
[0111] If an IP packet is received on the content facing interface, at 1136, the system 1100 can perform a lookup of a table containing a user equipment source NAT ranges, at 1138. If the route associated with the received IP packet is not in the user equipment source address table, at 1140, the IP packet can be discarded, at 1142, and any further processing of the IP packet can be terminated. If the route is in the user equipment source address table, at 1140, the system 1100 can provide the IP packet to the GTP/NAT daemon interface, at 1144. At 1146, the system 1100 can then determine whether the packet's destination IP address is allocated to existing TEID translation. If not, the IP packet is discarded, at 1142. If it has been allocated, then the system 1100 can translate NAT-range destination IP address to user equipment destination address, encapsulate it with matching GTP TEID, and set destination GTP IP address to target eNodeB, at 1148. At 1150, subsequent to the encapsulation, a GTP packet can be forwarded to the determined eNodeB using MNO facing interface.
Type 3 System
[0112]
[0113] Referring to
[0114] The external router 1225 can be communicatively coupled to the routers 1215, 1217 using a content offload network interface through which protocol neighbor sessions and offloaded content flows to/from user equipments can be transmitted. The router 1225 can include one or more processors that can perform IP route lookup and routing protocol processes (whereby UE network address translation range of routes can be determined by the router 1225). In particular, the router 1225 can be communicatively coupled with the routers/servers 1215, 1217 using specific IP routes (via the content offload network interface) and using default (e.g., 0/0) routes to MNO's PGW. The router 1225 can receive/transmit data from/to user equipments via interface 1209 of the system 1201.
[0115] Similar to
[0116]
[0117] Upon determination that a GTP packet has arrived on the MNO facing interface, at 1202, a determination can be made whether the GTP packet has been transmitted from mobile network operator's PGW, at 1204. If the GTP packet was transmitted from the mobile network operator's PGW, the system 1200 can access a state table to determine whether GTP TEID associated with the GTP packet is stored in that table, at 1230. If so, the GTP packet can be forwarded to the determined eNodeB associated with the UE TEID using the MNO facing port 802, at 1232-1234.
[0118] If it is determined that the GTP TEID of the GTP packet is not in the state at 1230, the GTP packet can be discarded, at 1228, and any further table, at forwarding/transmission of the GTP packet can end. Similarly, if, at 1204, it is determined that the GTP packet is not from mobile network operator's PGW, and it is not transmitted from mobile network operator's eNodeB, at 1206, the GTP packet can also be discarded, at 1228, thereby ending further processing of the GTP packet.
[0119] If it is determined that the GTP packet is from mobile network operator's eNodeB, at 1206, a determination whether the GTP TEID corresponds to a source NAT entry can be made, at 1208. If a stored source NAT entry does not exist, the system 1200 can allocate a source NAT entry to the GTP packet's TEID from a pool of entries, at 1210. Otherwise, if an entry already exists, the GTP packet can be de-encapsulated and a translation of the user equipment's source IP address can be performed by the system 1200, at 1212. Then, after translation, an IP packet can be provided to an external router via router-facing interface, as shown in
[0120] If an UE IP packet destined for MNO's PGW was received from an external router interface, at 1220, system 1200 can perform a lookup of the source IP address associated with the packet in the user equipment NAT table, translate source address to original user equipment source IP address, and encapsulate it with known GTP TEID and PGW destination information, at 1222. Then, the GTP packet can be forwarded to the determined PGW of the mobile network provider via MNO facing interface, at 1224.
[0121] If an IP packet is received on the content facing interface, at 1236, the system 1200 can perform a lookup of a table containing a user equipment source NAT ranges, at 1238. If the route associated with the received IP packet is not in the user equipment source address table, at 1240, the IP packet can be discarded, at 1242, and any further processing of the IP packet can be terminated. If the route is in the user equipment source address table, at 1240, the system 1200 can determine whether the packet's destination IP address is allocated to existing TEID translation, at 1246. If not, the IP packet is discarded, at 1242. If it has been allocated, then the system 1200 can translate NAT-range destination IP address to user equipment destination address, encapsulate it with matching GTP TEID, and set destination GTP IP address to target eNodeB, at 1248. At 1250, subsequent to the encapsulation, a GTP packet can be forwarded to the determined eNodeB using MNO facing interface.
Type 4 System
[0122]
[0123] Referring to
[0124] The GTP-U daemon 1313 can include components that can perform GTP encapsulation/de-encapsulation, determine UE TEID states, and can include an integrated IP routing information base (RIB). The GTP-U daemon 1313 and GTP-C S11 daemon 1315 can be communicatively coupled using a GTP TEID synchronization API interface, which can be used for transmission of data for the purposes of performing encapsulation/de-encapsulation of data packets. The packets 1329 and 1333 can be received, via the interface 1321 and kernel routing table 1319, and processed by the daemon 1313 encapsulation/de-encapsulation components. The control packets 1331 can be received by the daemon 1315 via the interface 1321 and kernel routing table 1319. The routing protocol daemon 1317 can push protocol RIB data to the GTP-U daemon 1313's RIB. The system 1330 differs from the system 1000 (shown in
[0125]
[0126] Upon determination that a GTP packet has arrived on the MNO facing interface, at 1302, a determination can be made whether the GTP packet has been transmitted from mobile network operator's PGW. If the GTP packet was transmitted from the mobile network operator's PGW, the system 1330 can perform functions of a typical serving gateway (SGW) and forward the GTP packet to eNodeB that has the particular TEID of the GTP packet, at 1308. Then, the GTP packet can be forwarded to the determined eNodeB associated with the UE TEID using the MNO facing interface, at 1310.
[0127] If, at 1304, it is determined that the GTP packet is not from mobile network operator's PGW, and it is not transmitted from mobile network operator's eNodeB, at 1306, the GTP packet can also be discarded, at 1312, thereby ending further processing of the GTP packet.
[0128] If it is determined that the GTP packet is from mobile network operator's eNodeB, at 1306, the system 1330 can determine whether the GTP packet contains an IP payload, at 1322. If not, the system 1330 perform functions of a typical serving gateway and forward the GTP packet to PGW that has the TEID of the GTP packet, at 1322, and the GTP packet can be forwarded to the determined PGW using the MNO facing interface, at 1324.
[0129] If the GTP packet contains an IP payload, at 1320, the system 1330 can determine whether the encapsulated user equipment's IP packet destination IP address is in the offload routing table, at 1314. If not, the system 1330 can perform processing operations 1322-1324, discussed above. Otherwise, the GTP packet can be de-encapsulated, at 1316 and the user equipment's IP packet can be forwarded to the indicated next-hop via content facing interface, at 1318.
[0130] If an IP packet is received on the content facing interface, at 1301, the system 1330 can determine whether content IP packet's destination IP address is contained in a GTP session table or contained in a network address translation session table (similar to the tables discussed above), at 1303. In this implementation, the system 1330 can access the GTP state table to determine whether the destination IP from the offload sources matches a known UE PDN IP address. If so, the packet can be delivered to the correct UE by following similar process as if the system 1330 was performing a NAT process, as discussed herein. If not, the IP packet can be discarded, at 1305, and any further processing of the IP packet can be terminated. Otherwise, at 1307, the system 1330 can encapsulate content IP packet with GTP header and associated TEID value for user equipment's destination address, at 1307. At 1309, subsequent to the encapsulation, a GTP packet can be forwarded to the determined eNodeB using MNO facing interface.
Type 5 System
[0131]
[0132] Referring to
[0133] The external router 1425 can be communicatively coupled to the routers 1415, 1417 using a content offload network interface through which protocol neighbor sessions and offloaded content flows to/from user equipments can be transmitted. The router 1425 can include one or more processors that can perform IP forwarding, network address translation, and routing protocol processes. In particular, the router 1425 can be communicatively coupled with the routers/servers 1415, 1417 using specific IP routes (via the content offload network interface) and using default (e.g., 0/0) routes to MNO's PGW. The router 1425 can receive/transmit data from/to user equipments via interface 1409 of the system 1401.
[0134] The GTP-U daemon 1405 can include components that can perform GTP encapsulation/de-encapsulation and determine UE TEID and IP access point name (APN) states. The GTP-U daemon 1405 and GTP-C S11 daemon 1403 can be communicatively coupled using a GTP TEID synchronization API interface, which can be used for transmission of data for the purposes of performing encapsulation/de-encapsulation of data packets. The packets 1419 and 1423 can be received, via the interface 1411, and processed by the daemon 1405 encapsulation/de-encapsulation components. The control packets 1421 can be received by the daemon 1403 via the interface 1411.
[0135]
[0136] MNO facing interface or an IP packet arrived on the content facing interface or if a UE IP packet destined for PGW arrived from an external router. If the GTP packet arrived on the MNO facing interface, the system 1400 can perform processing operations 1402-1412, 1424-1434. If IP packet arrived from an external router, operations 1420-1424 can be performed. If the IP packet arrived on the content facing interface, the system 1400 can perform processing operations 1436-1450.
[0137] Upon determination that a GTP packet has arrived on the MNO facing interface, at 1402, a determination can be made whether the GTP packet has been transmitted from mobile network operator's PGW, at 1404. If the GTP packet was transmitted from the mobile network operator's PGW, the system 1400 can access a state table to determine whether GTP TEID associated with the GTP packet is stored in that table, at 1430. If so, the GTP packet can be forwarded to the determined eNodeB associated with the UE TEID using the MNO facing port 802, at 1432-1434.
[0138] If it is determined that the GTP TEID of the GTP packet is not in the state table, at 1430, the GTP packet can be discarded, at 1428, and any further forwarding/transmission of the GTP packet can end. Similarly, if, at 1404, it is determined that the GTP packet is not from mobile network operator's PGW, and it is not transmitted from mobile network operator's eNodeB, at 1406, the GTP packet can also be discarded, at 1428, thereby ending further processing of the GTP packet.
[0139] If it is determined that the GTP packet is from mobile network operator's eNodeB, at 1406, a determination whether the GTP tunnel contains payload IP information, at 1408. If so, the GTP packet can be de-encapsulated, at 1412. Then, after de-encapsulation, an IP packet can be transmitted to an external router (e.g., router 1425) via router-facing interface, as shown in
[0140] If an UE IP packet destined for MNO's PGW was received from an external router interface, at 1420, system 1400 can perform a lookup of the source IP address associated with the packet in the user equipment IP table (similar to the GTP tables discussed above) and encapsulate it with known GTP TEID and PGW destination information, at 1422. Then, the GTP packet can be forwarded to the determined PGW of the mobile network provider via MNO facing interface 1 1411, at 1424.
[0141] If an IP packet (destined for the user equipment) is received on the content facing interface from an external router interface, at 1436, the system 1400 can perform a lookup of the user equipment IP table containing destination IP addresses, at 1438. If the route associated with the received IP packet is not in the user equipment IP table, at 1446, the IP packet can be discarded, at 1442, and any further processing of the IP packet can be terminated. If the route is in the user equipment IP table, at 1446, the system 1400 can encapsulate it with matching GTP TEID and set destination GTP IP address to a target eNodeB, at 1448. At 1450, subsequent to the encapsulation, a GTP packet can be forwarded to the determined eNodeB using MNO facing interface 1 1411.
[0142] In some implementations, the current subject matter can be configured to be implemented in a system 1500, as shown in
[0143]
[0144] In some implementations, the current subject matter can include one or more of the following optional features. The packet can be received by a local IP access appliance system that can be communicatively coupled to at least one component operated by a mobile network operator (e.g., eNodeB, Ethernet switch(es), backhaul network, evolved packet core (including SGW, PGW, PCRF, MME, etc.) and at least one content provider (e.g., content provider server(s)). The packet received by the local IP access appliance system can include at least one of: an IP packet received from the content provider and a GTP packet received from at least one component operated by the mobile network operator.
[0145] If the packet is a GTP packet received from an evolved packet core operated by the mobile network operator, the GTP packet is forwarded to an eNodeB operated by the mobile network operator. If the GTP packet is received from an eNodeB operated by the mobile network operator, at least one encapsulated IP packet (e.g., from a user equipment communicatively coupled to the eNodeB) contained in the GTP packet can be inspected and routed based on the determined encapsulated destination address of the IP packet. The routing includes a determination whether to route the packet along the known content route or the default content route. The GTP packet can be de-encapsulated and a network address translation can be performed if the determined destination address is the known content route, which causes the IP packet to be forwarded to the content provider. Otherwise, if the route is determined to be the default content route, the GTP packet is re-encapsulated and transmitted to the evolved packet core operated by the mobile network operator.
[0146] If the packet is an IP packet received from the content provider, the packet is transmitted to a user equipment communicatively coupled to an eNodeB operated by the mobile network operator. The transmission of the packet can performed using a GTP TEID, which can be determined by the mobile network operator (i.e., MME of the evolved packet core operated by the mobile network operator).
[0147] The systems and methods disclosed herein can be embodied in various forms including, for example, a data processor, such as a computer that also includes a database, digital electronic circuitry, firmware, software, or in combinations of them. Moreover, the above-noted features and other aspects and principles of the present disclosed implementations can be implemented in various environments. Such environments and related applications can be specially constructed for performing the various processes and operations according to the disclosed implementations or they can include a general-purpose computer or computing platform selectively activated or reconfigured by code to provide the necessary functionality. The processes disclosed herein are not inherently related to any particular computer, network, architecture, environment, or other apparatus, and can be implemented by a suitable combination of hardware, software, and/or firmware. For example, various general-purpose machines can be used with programs written in accordance with teachings of the disclosed implementations, or it can be more convenient to construct a specialized apparatus or system to perform the required methods and techniques.
[0148] The systems and methods disclosed herein can be implemented as a computer program product, i.e., a computer program tangibly embodied in an information carrier, e.g., in a machine readable storage device or in a propagated signal, for execution by, or to control the operation of, data processing apparatus, e.g., a programmable processor, a computer, or multiple computers. A computer program can be written in any form of programming language, including compiled or interpreted languages, and it can be deployed in any form, including as a stand-alone program or as a module, component, subroutine, or other unit suitable for use in a computing environment. A computer program can be deployed to be executed on one computer or on multiple computers at one site or distributed across multiple sites and interconnected by a communication network.
[0149] As used herein, the term user can refer to any entity including a person or a computer.
[0150] Although ordinal numbers such as first, second, and the like can, in some situations, relate to an order; as used in this document ordinal numbers do not necessarily imply an order. For example, ordinal numbers can be merely used to distinguish one item from another. For example, to distinguish a first event from a second event, but need not imply any chronological ordering or a fixed reference system (such that a first event in one paragraph of the description can be different from a first event in another paragraph of the description).
[0151] The foregoing description is intended to illustrate but not to limit the scope of the invention, which is defined by the scope of the appended claims. Other implementations are within the scope of the following claims.
[0152] These computer programs, which can also be referred to programs, software, software applications, applications, components, or code, include machine instructions for a programmable processor, and can be implemented in a high-level procedural and/or object-oriented programming language, and/or in assembly/machine language. As used herein, the term machine-readable medium refers to any computer program product, apparatus and/or device, such as for example magnetic discs, optical disks, memory, and Programmable Logic Devices (PLDs), used to provide machine instructions and/or data to a programmable processor, including a machine-readable medium that receives machine instructions as a machine-readable signal. The term machine-readable signal refers to any signal used to provide machine instructions and/or data to a programmable processor. The machine-readable medium can store such machine instructions non-transitorily, such as for example as would a non-transient solid state memory or a magnetic hard drive or any equivalent storage medium. The machine-readable medium can alternatively or additionally store such machine instructions in a transient manner, such as for example as would a processor cache or other random access memory associated with one or more physical processor cores.
[0153] To provide for interaction with a user, the subject matter described herein can be implemented on a computer having a display device, such as for example a cathode ray tube (CRT) or a liquid crystal display (LCD) monitor for displaying information to the user and a keyboard and a pointing device, such as for example a mouse or a trackball, by which the user can provide input to the computer. Other kinds of devices can be used to provide for interaction with a user as well. For example, feedback provided to the user can be any form of sensory feedback, such as for example visual feedback, auditory feedback, or tactile feedback; and input from the user can be received in any form, including, but not limited to, acoustic, speech, or tactile input.
[0154] The subject matter described herein can be implemented in a computing system that includes a back-end component, such as for example one or more data servers, or that includes a middleware component, such as for example one or more application servers, or that includes a front-end component, such as for example one or more client computers having a graphical user interface or a Web browser through which a user can interact with an implementation of the subject matter described herein, or any combination of such back-end, middleware, or front-end components. The components of the system can be interconnected by any form or medium of digital data communication, such as for example a communication network. Examples of communication networks include, but are not limited to, a local area network (LAN), a wide area network (WAN), and the Internet.
[0155] The computing system can include clients and servers. A client and server are generally, but not exclusively, remote from each other and typically interact through a communication network. The relationship of client and server arises by virtue of computer programs running on the respective computers and having a client-server relationship to each other.
[0156] The implementations set forth in the foregoing description do not represent all implementations consistent with the subject matter described herein. Instead, they are merely some examples consistent with aspects related to the described subject matter. Although a few variations have been described in detail above, other modifications or additions are possible. In particular, further features and/or variations can be provided in addition to those set forth herein. For example, the implementations described above can be directed to various combinations and sub-combinations of the disclosed features and/or combinations and sub-combinations of several further features disclosed above. In addition, the logic flows depicted in the accompanying figures and/or described herein do not necessarily require the particular order shown, or sequential order, to achieve desirable results. Other implementations can be within the scope of the following claims.