Next Generation Multicast – NG-MVPN
Introduction
Multicast is a great technology that although it provides great benefits, is seldomly deployed. It’s a lot like IPv6 in that regard. Service providers or enterprises that run MPLS and want to provide multicast services have not been able to use MPLS to provide multicast Multicast has then typically been delivered by using Draft Rosen which is a mGRE technology to provide multicast. This post starts with a brief overview of Draft Rosen.
Draft Rosen
Draft Rosen uses GRE as an overlay protocol. That means that all multicast packets will be encapsulated inside GRE. A virtual LAN is emulated by having all PE routers in the VPN join a multicast group. This is known as the default Multicast Distribution Tree (MDT). The default MDT is used for PIM hello’s and other PIM signaling but also for data traffic. If the source sends a lot of traffic it is inefficient to use the default MDT and a data MDT can be created. The data MDT will only include PE’s that have receivers for the group in use.
Draft Rosen is fairly simple to deploy and works well but it has a few drawbacks. Let’s take a look at these:
- Overhead – Continue reading

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