Cisco Technology, Inc.

Tony Speakman

Dino Farinacci

Lorenzo Vicisano

Hasmit S Grover

Victor Manuel Moreno

Dhananjaya Rao

Isidor Kouvelas

Nair Venugopal

Steven P Lin

Alex G Tweedly

Ijsbrand Wijnands

Arjen Boers

Yiqun Cai

In one embodiment, an apparatus includes one or more internal interfaces in communication with one or more network devices in a first network site through a Layer 2 link, an overlay interface in communication through a Layer 3 link with a core network connected to one or more other network sites, and a table mapping addresses for network devices in the other network sites to addresses of edge devices in the same network site as the network device. The apparatus further includes a processor operable to encapsulate a packet received at one of the internal interfaces and destined for one of the network devices in the other network sites, with an IP header including a destination address of the edge device mapped to the destination network device, and forward the encapsulated packet to the core network.

Overlay transport virtualization

A method and apparatus for repopulating a forwarding information base at a network device are disclosed. In one embodiment, the apparatus includes a routing information base, forwarding information base, memory for storing performance data based on packets forwarded from the network device, and a processor configured to prioritize routes stored in the routing information base based on the performance data, propagate the routes from the routing information base to the forwarding information base in an order based at least in part on the route priorities.

Statistics based forwarding information base repopulation

Improved systems and methods for implementing data-driven protocols are provided. In one embodiment, improved implementations of multicast routing protocols are provided. Separation between multicast forwarding and control elements are provided by use of a powerful yet simple application program interface (API) for inter-module communication. The API is multicast-routing-protocol-independent and can be used to express the forwarding state of any existing multicast protocol. Efficient platform-specific implementations are facilitated.

Multicast-routing-protocol-independent realization of IP multicast forwarding

A multicast transmission scheme is introduced. A multicast data stream is sent on a default tunnel and switched to a data tunnel during flooding conditions. The default tunnel is a point-to-multipoint tunnel from, for example, a source provider edge router to all other provider edge routers in a virtual private network. The data tunnel is a point-to-multipoint tunnel from, for example, a source provider edge router to other provider edge routers that have recipients. Flooding conditions can occur when sending the multicast data stream on the default tunnel, for example, when a specified bandwidth threshold has been exceeded on a source provider edge router. Additionally, the data tunnel is created by selecting a multicast distribution tunnel group from a configured pool of addresses, advertising the group, receiving data joins from, for example, provider edge routers with recipients, and waiting a specified send time.

Flooding control for multicast distribution tunnel

The invention provides a convenient and expandable method for transmitting one or more loss rate statistics determined in a distributed manner from a multicast distribution tree to a source computer. First, the loss rate statistics are collected in a distributed manner from target receiver stations, and from routers in the multicast distribution tree. Second, there is a distributed calculation of statistics on loss rate by routers in the multicast distribution tree. Third, there is transportation of the loss rate statistics back to the source computer in reverse along the multicast distribution tree. For example, congestion information is collected by routers, and the congestion information is sent upstream to the multicast source station in fields of NAK messages. A router may receive a NAK packet in transit from an intended destination station to a source station, the NAK packet indicating loss of a data packet. The router writes a loss rate statistic determined by the router into a 'loss rate field' of a message to be sent upstream along the reverse of the distribution tree. The router determines the loss rate statistic to be written into the loss rate field of the message, in response to: analyzing the loss rate statistics on each of its links; the loss rate reported by the incoming NAK packet; and, the elapsed time from the time stamp showing when the various loss rate statistics were determined.

Router-assisted multicast congestion control

The invention provides a method and system for content-based filtering of multicast information. A set of sources (S) which desire to distribute potentially large numbers of categories of differing information each associates a content descriptor (CD) with messages including information in those categories, so that a set of recipients (R) can receive information in at least some of those categories. A mapping server (M) associates a multicast address (MA) and a content mask (CM) with each content descriptor, so that network elements (N), such as routers, in the network can distribute only those messages which are of interest to recipients in multicast distribution trees for those multicast addresses. Each source generates content descriptors for each differentiable topic in a tree structured hierarchy, and obtains a multicast address and a content mask for the broadest content descriptor it is capable of distributing. Each recipient obtains the associated source, multicast address, and content mask, for each content descriptor of interest, and uses that information to join the multicast distribution tree for that information. Each network element between the source and the recipient determines what information it must forward for further distribution in response to the content descriptors, content masks, multicast addresses, and multicast distribution trees.

Growing community of inventors

San Francisco, CA, United States of America

Tony Speakman