Configuring RSVP-TE Refresh Mechanism

Context

Enabling Srefresh in the mpls view on two nodes that are the neighbors of each other can reduce the cost and improve the performance of a network. In the MPLS view, Srefresh can be enabled on the entire device. After Srefresh is enabled, the retransmission of Srefresh messages is automatically enabled on the interface or the device.

The Srefresh mechanism in MPLS view is applied to the TE FRR networking. Srefresh is enabled globally on the Point of Local Repair (PLR) and Merge Point (MP) over an FRR bypass tunnel. This allows efficient use of network resources and improves Srefresh reliability.

Assume that a node initializes the retransmission interval as Rf seconds. If receiving no ACK message within Rf seconds, the node retransmits the RSVP message after (1 + Delta) x Rf seconds. The value of Delta depends on the link rate. The node retransmits the message until it receives an ACK message or the times of retransmission reach the threshold (that is, retransmission increment value).

Perform the following configurations on each node of the MPLS TE tunnel.

Procedure

Perform the following steps in the MPLS view.
1. Run system-view
  The system view is displayed.
2. Run mpls
  The MPLS view is displayed.
3. Run mpls rsvp-te srefresh
  Srefresh is enabled.
  
  By default, Srefresh is disabled globally.
Perform the following steps in the interface view.
1. Run system-view
  The system view is displayed.
2. Run interface interface-type interface-number
  The interface view is displayed.
3. (Optional) On an Ethernet interface, run undo portswitch
  The interface is switched to Layer 3 mode.
  
  By default, an Ethernet interface works in Layer 2 mode.
  
  Only the S5720-EI, S5720-HI, S5730-HI, S5731-H, S5731-S, S5731S-H, S5731S-S, S5732-H, S6720-EI, S6720-HI, S6720S-EI, S6730-H, S6730S-H, S6730-S, and S6730S-S support switching between Layer 2 and Layer 3 modes.
4. Run mpls rsvp-te srefresh
  Srefresh is enabled.
  
  By default, Srefresh is disabled on all interfaces.
5. (Optional) Run mpls rsvp-te timer retransmission { increment-value increment | retransmit-value interval } ^*
  The retransmission parameters are set.
  
  By default, increment is set to 1, and interval is set to 5000 milliseconds.