Restrictions for MPLS-TE Automatic Bandwidth
When the automatic bandwidth cannot update the tunnel bandwidth, the following restrictions are listed:
•
Tunnel is in a fast reroute (FRR) backup, active, or path protect active state. This occurs because of the
assumption that protection is a temporary state, and there is no need to reserve the bandwidth on a backup
tunnel. You should prevent taking away the bandwidth from other primary or backup tunnels.
•
Reoptimization fails to occur during a lockdown. In this case, the automatic bandwidth does not update
the bandwidth unless the bandwidth application is manually triggered by using the mpls traffic-eng
auto-bw apply command in EXEC mode.
Related Topics
Forcing the Current Application Period to Expire Immediately, on page 290
Point-to-Multipoint Traffic-Engineering
Point-to-Multipoint Traffic-Engineering Overview
The Point-to-Multipoint (P2MP) Resource Reservation Protocol-Traffic Engineering (RSVP-TE) solution
allows service providers to implement IP multicast applications, such as IPTV and real-time video, broadcast
over the MPLS label switch network. The RSVP-TE protocol is extended to signal point-to-point (P2P) and
P2MP label switched paths (LSPs) across the MPLS and GMPLS networks.
By using RSVP-TE extensions as defined in RFC 4875, multiple subLSPs are signaled for a given TE source.
The P2MP tunnel is considered as a set of Source-to-Leaf (S2L) subLSPs that connect the TE source to
multiple leaf Provider Edge (PE) nodes.
At the TE source, the ingress point of the P2MP-TE tunnel, IP multicast traffic is encapsulated with a unique
MPLS label, which is associated with the P2MP-TE tunnel. The traffic continues to be label-switched in the
P2MP tree. If needed, the labeled packet is replicated at branch nodes along the P2MP tree. When the labeled
packet reaches the egress leaf (PE) node, the MPLS label is removed and forwarded onto the IP multicast tree
across the PE-CE link.
To enable end-to-end IP multicast connectivity, RSVP is used in the MPLS-core for P2MP-TE signaling and
PIM is used for PE-CE link signaling.
•
All edge routers are running PIM-SSM or Source-Specific Multicast (SSM) to exchange multicast routing
information with the directly-connected Customer Edge (CE) routers.
•
In the MPLS network, RSVP P2MP-TE replaces PIM as the tree building mechanism, RSVP-TE grafts
or prunes a given P2MP tree when the end-points are added or removed in the TE source configuration
(explicit user operation).
These are the definitions for Point-to-Multipoint (P2MP) tunnels:
Source
Configures the node in which Label Switched Path (LSP) signaling is initiated.
Cisco IOS XR MPLS Configuration Guide for the Cisco CRS Router, Release 5.1.x
193
Implementing MPLS Traffic Engineering
Point-to-Multipoint Traffic-Engineering
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