MPLS traffic engineering

[Ratheesh mv]

Hi everyone ,

In the attachment of MPLS traffic engineering path calculation ,If TE metric is equal on multiple paths then "path with the highest available bandwidth" is preferred.(Tie break)

I am bit confused on this statement. What does it mean by "path with the highest available bandwidth"?

Whether is it RSVP reserve bandwidth or something else ?

 Thanks in advance 

[Abzal]

Hi,

RSVP-TE reserves bw for a TE tunnel and IGP floods available bw information out of max reservable bw. So either head-end router or PCE takes into account when calculates an LSP path for requested tunnel.

[Ratheesh mv]

MPLS TE has been configured between head-end and tail-end with below mentioned parameters. (Tunnel established over R2)

MPLS TE tunnel demand bandwidth 10 mpbs. RSVP reserve bandwidth is 50 mbps on all interfaces along the path. MPLS TE metric is equal on all paths .MPLS TE priority is default 

My requirement is I would like to establish MPLS TE over R4 but I dont want to play with MPLS-TE metric .

I would like to know that how can I play with "path with the highest available bandwidth" ?

As I mentioned RSVP bandwidth is 50 mbps on all interfaces along the path.

Thanks in advance 

[balaji.bandi · Accepted solution]

as it stands the statement "path with the highest available bandwidth" is preferred" this is preferred path for the packet when the TIE break.

how the process and calculation and RSPV based on the config :

some example for reference to understand  :

https://www.ciscopress.com/articles/article.asp?p=426640&seqNum=3

https://sites.google.com/site/amitsciscozone/home/important-tips/traffic-engineering/mpls-te-basics

[Ratheesh mv]

MPLS TE has been configured between head-end and tail-end with below mentioned parameters. (Tunnel established over R2)

MPLS TE tunnel demand bandwidth 10 mpbs. RSVP reserve bandwidth is 50 mbps on all interfaces along the path. MPLS TE metric is equal on all paths .MPLS TE priority is default 

My requirement is I would like to establish MPLS TE over R4 but I dont want to play with MPLS-TE metric .

I would like to know that how can I play with "path with the highest available bandwidth" ?

As I mentioned RSVP bandwidth is 50 mbps on all interfaces along the path.

Thanks in advance 

[Abzal]

Hi,

There is only one LSP path over R4 if your tail-end router is R5.

For example if you skip explicit path and set it dynamic with all equal MPLS-TE metrics on all links then:

1st tiebreaker is shortest IGP path from head-end to tail-end router.

2nd tiebreaker is a path with the highest available bandwidth (for example if you have another existing MPLS-TE tunnel)

3rd if there more than 1 path then CSPF selects one randomly.