The MPLS WG Archive

["Anu Divya" <anudivka@rediffmail.com>]

Hi, 
 
i have few doubts about how to use bandwidth information while calculating a constrined based path.

according to RFC 3630 (TE Extensions to OSPF version 2)
there are three kinds of bandwidth 

2.5.6 Maximum Bandwidth.
2.5.7 Maximum Reservable Bandwidth.
2.5.8 Unreserved Bandwidth.

if an application ask for a constrined based path in which bandwidth constrain is X mbps.

now should i consider only those TE links which has Unreserved Bandwidth at particular priority greater than  X Mbps.
or i should also consider the Maximum Bandwidth (True Link Capacity). 

my doubt is:-

whether the check should be like this 
      Unreserved Bandwidth [priority]  >= X Mbps

or 
      (Unreserved Bandwidth [priorit] >= X Mbps)  && 
      (Maximum Bandwidth >= X Mbps)
    


according to draft Routing Extensions in Support of generalised MPLS (draft-ietf-ccamp-gmpls-routing-06.txt)
there are two more bandwidth 

Maximum LSP bandwidth.
Minimum LSP bandwidth. 

now say if the application ask for a path in which bandwidth constrain is X Mbps. 

now the check should be like this 
     Minimum LSP bandwidth < X Mbps < Maximum LSP bandwidth 

or 

     Minimum LSP bandwidth < X Mbps < 
     minimum (Maximum LSP bandwidth, Unreserved Bandwidth)
       

Regards