Help us improve your experience.

Let us know what you think.

Do you have time for a two-minute survey?

 

Understanding MBGP Multicast VPN Extranets

 

A multicast VPN (MVPN) extranet enables service providers to forward IP multicast traffic originating in one VPN routing and forwarding (VRF) instance to receivers in a different VRF instance. This capability is also know as overlapping MVPNs.

The MVPN extranet feature supports the following traffic flows:

  • A receiver in one VRF can receive multicast traffic from a source connected to a different router in a different VRF.

  • A receiver in one VRF can receive multicast traffic from a source connected to the same router in a different VRF.

  • A receiver in one VRF can receive multicast traffic from a source connected to a different router in the same VRF.

  • A receiver in one VRF can be prevented from receiving multicast traffic from a specific source in a different VRF.

MBGP Multicast VPN Extranets Application

An MVPN extranet is useful in the following applications.

Mergers and Data Sharing

An MVPN extranet is useful when there are business partnerships between different enterprise VPN customers that require them to be able to communicate with one another. For example, a wholesale company might want to broadcast inventory to its contractors and resellers. An MVPN extranet is also useful when companies merge and one set of VPN sites needs to receive content from another VPN. The enterprises involved in the merger are different VPN customers from the service provider point of view. The MVPN extranet makes the connectivity possible.

Video Distribution

Another use for MVPN extranets is video multicast distribution from a video headend to receiving sites. Sites within a given multicast VPN might be in different organizations. The receivers can subscribe to content from a specific content provider.

The PE routers on the MVPN provider network learn about the sources and receivers using MVPN mechanisms. These PE routers can use selective trees as the multicast distribution mechanism in the backbone. The network carries traffic belonging only to a specified set of one or more multicast groups, from one or more multicast VPNs. As a result, this model facilitates the distribution of content from multiple providers on a selective basis if desired.

Financial Services

A third use for MVPN extranets is enterprise and financial services infrastructures. The delivery of financial data, such as financial market updates, stock ticker values, and financial TV channels, is an example of an application that must deliver the same data stream to hundreds and potentially thousands of end users. The content distribution mechanisms largely rely on multicast within the financial provider network. In this case, there could also be an extensive multicast topology within brokerage firms and banks networks to enable further distribution of content and for trading applications. Financial service providers require traffic separation between customers accessing the content, and MVPN extranets provide this separation.