MPLS TE Path Bandwidth
Table of Contents
Introduction
Bandwidth of a TE tunnel can be included as a path setup option. Paths that have enough available bandwidth for reservation will pass the Constrained-Based Shortest Path First (CSPF).
Path Bandwidth
- By default, when enabling the RSVP TE feature 0 Kbps is reserved for RSVP. Make sure to enable the correct amount or 75% of the interface's bandwidth is set under each MPLS TE interface.
- This feature only works under the control plane. It does not enforce or measure any actual data plane bandwidth going through the tunnel.
- To control the bandwidth, use policing on the tunnel's head end.
- Bandwidth requirements of each tunnel is calculated per each priority group. There are 8 total priorities see MPLS-TE-Path-Setup-Priority-Hold for details of the feature.
- In Cisco's implementation the available BW of only current and lower priorities is subtracted. Higher priorities (lower values) don't change to allow higher priority tunnels to take preference. See example below.
- The priority values in the output of sh ip ospf mpls traffic-eng link is in bytes per second.
Priority 0 : 125000 Priority 1 : 125000
Priority 2 : 125000 Priority 3 : 125000
Priority 4 : 125000 Priority 5 : 62500 <----- bytes per second
Priority 6 : 62500 Priority 7 : 62500
Relevant Commands
ip rsvp bandwidth
R1(config-if)# ip rsvp bandwidth [kbps]
tunnel mpls traffic-engineering bandwidth
Defines the required reservation bandwidth value for the TE Tunnel. Configured under the tunnel's interface configuration mode.
R1(config-if)# tunnel mpls traffic-engineering bandwidth [kbps]
Show mpls traffic-eng topology
Shows TE topological information such as bandwidth used per each priority on a TE link.
show mpls traffic-eng topology
Show ip ospf mpls traffic-eng link
Shows the OSPF TE information per attached links.
show ip ospf mpls traffic-eng link