Cisco Cisco IOS Software Release 15.0(1)S
MLDP-Based MVPN
Information About MLDP-Based MVPN
4
The only transport mechanism previously available was Protocol Independent Multicast (PIM) with
Multipoint Generic Routing Encapsulation (mGRE) over an IP core network. The introduction of
Multicast Label Distribution Protocol (MLDP) provides transport by using MLDP with label
encapsulation over an MPLS core network.
Multipoint Generic Routing Encapsulation (mGRE) over an IP core network. The introduction of
Multicast Label Distribution Protocol (MLDP) provides transport by using MLDP with label
encapsulation over an MPLS core network.
MLDP creates the MDTs as follows:
•
The default MDT uses MP2MP LSPs.
–
Supports low bandwidth and control traffic between VRFs.
•
The data MDT uses P2MP LSPs.
–
Supports a single high-bandwidth source stream from a VRF.
All other operations of MVPN remain the same regardless of the tunneling mechanism:
•
PIM neighbors in a VRF are seen across a Label Switched Path virtual interface (LSP-VIF).
•
The VPN multicast state is signaled by PIM.
The only other difference when using MLDP is that the MDT group address used in the mGRE solution
is replaced with a VPN ID.
is replaced with a VPN ID.
Benefits of MLDP-Based MVPN
•
Enables the use of a single MPLS forwarding plane for both unicast and multicast traffic.
•
Enables existing MPLS protection (for example, MPLS Traffic Engineering/Resource Reservation
Protocol (TE/RSVP link protection) and MPLS Operations Administration and Maintenance (OAM)
mechanisms to be used for multicast traffic.
Protocol (TE/RSVP link protection) and MPLS Operations Administration and Maintenance (OAM)
mechanisms to be used for multicast traffic.
•
Reduces operational complexity due to the elimination of the need for PIM in the MPLS core
network.
network.
Initial Deployment of an MLDP-Based MVPN
Initial deployment of an MLDP-based MVPN involves the configuration of a default MDT and one or
more data MDTs.
more data MDTs.
A static default MDT is established for each multicast domain. The default MDT defines the path used
by PE routers to send multicast data and control messages to every other PE router in the multicast
domain. A default MDT is created in the core network using a single MP2MP LSP.
by PE routers to send multicast data and control messages to every other PE router in the multicast
domain. A default MDT is created in the core network using a single MP2MP LSP.
An MLDP-based MVPN also supports the dynamic creation of data MDTs for high-bandwidth
transmission.
transmission.
Default MDT Creation
shows the default MDT scenario. The Opaque value used to signal a default MDT consists of
two parameters: the VPN ID and the MDT number for the VPN in the format (vpn-id, 0) where vpn-id
is a manually configured 7-byte number that uniquely identifies this VPN. The default MDT is set to
zero.
is a manually configured 7-byte number that uniquely identifies this VPN. The default MDT is set to
zero.
In this scenario, each of the three PE routers belong to the VRF called VRF and they have the same VPN
ID. Each PE router with the same VPN ID will join the same MP2MP tree. The PE routers have created
a primary MP2MP tree rooted at P-Central (Root 1) and a backup MP2MP tree rooted at PE-North (Root
ID. Each PE router with the same VPN ID will join the same MP2MP tree. The PE routers have created
a primary MP2MP tree rooted at P-Central (Root 1) and a backup MP2MP tree rooted at PE-North (Root