Controller(s) in a software defined network (SDN) are able to determine a control path towards each network switch by performing a switch-originated discovery and using an in-band control network that is an overlay on the data network. A topology tree is maintained, where each controller being the root of the tree, and where messages from the root to any switch may pass through neighboring switches to reach that switch (and vice-versa). Each switch in the SDN attempts to connect to the controller when it does not have a readily configured control connection towards the controller. Once the controller learns about the presence of a new switch and at least one or more paths to reach that switch through a novel discovery process, it can select, adjust and even optimize the control path's route towards that switch.

In an example embodiment, a specialized architecture is utilized in conjunction with a message broker to enable asynchronous communications. The specialized architecture provides central components within each data center to enable the communication, and also is able to segregate functionality across different microservice landscapes. A message broker alone may not be sharable across data centers for various technical reasons, such as security concerns, latency, or other technical constraints. Topic names may be utilized by the message broker to ensure delivery of the message to the correct microservice in the other data center.

The techniques disclosed herein provide a system that can generate targeted positioning of message content for multi-user communication interfaces. In some configurations a system may generate a user interface that displays a number of video stream renderings, wherein individual video stream renderings, e.g., thumbnail views, show a participant of a communication session. When one of the participants sends the user a private message, the system renders at least a portion of the private message in a semi-transparent format as an overlay on the video rendering of the sender. This allows a traditional video stream interface to also function as an organizer for private messages sent to a particular user. This user interface format allows a user to readily identify a broader perspective of chat activity without requiring a user to enter specific chat user interfaces or provide a number of manual input entries to view the private chat content.

The techniques disclosed herein provide a system that can generate targeted positioning of message content for multi-user communication interfaces. In some configurations a system may generate a user interface that displays a number of video stream renderings, wherein individual video stream renderings, e.g., thumbnail views, show a participant of a communication session. When one of the participants sends the user a private message, the system renders at least a portion of the private message in a semi-transparent format as an overlay on the video rendering of the sender. This allows a traditional video stream interface to also function as an organizer for private messages sent to a particular user. This user interface format allows a user to readily identify a broader perspective of chat activity without requiring a user to enter specific chat user interfaces or provide a number of manual input entries to view the private chat content.

A path establishment method and a controller are disclosed. The method includes: when detecting a path establishment request for establishing P2MP TE, computing a P2MP TE path by using head node information and tail node information included in the path establishment request; identifying a target branch node in the P2MP TE path, and obtaining a label of the target branch node; and when a third node corresponding to the head node information and the target branch node are not a same node, sending first information to the third node, and sending second information to the target branch node, where the second information is used to instruct the target branch node to generate a multicast forwarding entry. Embodiments of this application can reduce complexity of establishing the P2MP TE path.

In one example, a system comprises a plurality of non-last-hop routers (non-LHRs) of a network, the non-LHRs configured with a multicast distribution tree for a multicast group to transport first multicast packets of a multicast flow toward one or more LHRs, wherein a router of the non-LHR routers is configured to receive unicast packets for an application session associated with the multicast group, encapsulate the unicast packets in a multicast header to generate the first multicast packets for distribution using the multicast distribution tree, and output the first multicast packets; and the one or more LHRs, wherein the one or more LHRs are interested receivers of the multicast group, and wherein the one or more LHRs are configured to receive the first multicast packets of the multicast flow, extract the unicast packets for the application session, and send the unicast packets to one or more clients of the application session.

In some examples, a method includes receiving, by an egress network device for a network, messages from each of a plurality of ingress network devices for the network, wherein each of the messages specifies a multicast source, a multicast group, and an upstream multicast hop weight value for multicast traffic for the multicast source and the multicast group; selecting, by the egress network device and based on the upstream multicast hop weight values specified by the received messages, one of the plurality of ingress network devices to which to send a multicast join message of a plurality of multicast join messages for the multicast source and multicast group; and sending, by the egress network device, the multicast join message to the selected one of the plurality of ingress network devices.

In some embodiments, a method processes a first packet and generates a first copy of the first packet as a second packet. The method sends second copies of the first packet to a first group of multiple destinations defined by a first address. Also, the method sends the second packet to an interface with a loopback function. The interface recirculates the second packet for further processing. The second packet is processed where the second packet is assigned a destination of a second address. Then, the method sends copies of the second packet to a second group of multiple destinations defined by the second address.

Communication apparatus includes multiple interfaces connected to a packet data network, and a memory coupled to the interfaces and configured as a buffer to contain packets received through ingress interfaces while awaiting transmission to the network via respective egress interfaces. Packet processing logic is configured, upon receipt of a test packet through an ingress interface of the apparatus, to allocate a space in the buffer for storage of a single copy of the test packet, to replicate and transmit sequentially multiple copies of the stored copy of the test packet through a designated egress interface, to receive an indication of a number of copies of the test packet that are to be transmitted, and responsively to the indication, to terminate replication of the test packet and release the allocated space in the buffer.

In some examples, a method includes receiving, by an egress network device for a network, messages from each of a plurality of ingress network devices for the network, wherein each of the messages specifies a multicast source, a multicast group, and an upstream multicast hop weight value for multicast traffic for the multicast source and the multicast group; selecting, by the egress network device and based on the upstream multicast hop weight values specified by the received messages, one of the plurality of ingress network devices to which to send a multicast join message of a plurality of multicast join messages for the multicast source and multicast group; and sending, by the egress network device, the multicast join message to the selected one of the plurality of ingress network devices.