Subject: RE: Best Effort LSP's Bandwidth

From: Shahram Davari <[email-masked]>
Date: Mon, 8 May 2000 07:14:40 -0700

Hi,

According to Diffserv, some BW MUST be reserved for BE in each hop. This BW
may be used during path computation for the QoS LSPs. 

Currently the BW assigned to each Diffserv class (including the BE) is
provisioned and can only be changed by management. The RSVP-TE and CR-LDP
only act as admission control in rejecting or accepting LSPs. 

However, it is quite possible for a node to measure the actual traffic in
each class (including BE) and report that in IGP advertisements. Then the
RSVP-TE or CR-LDP can use this information to borrow BW from other classes,
if during the LSP setup enough BW is not available. 

Regards,
-Shahram

>-----Original Message-----
>From: MPLS [mailto:[email-masked]]
>Sent: Saturday, May 06, 2000 6:59 PM
>To: [email-masked]
>Subject: Best Effort LSP's Bandwidth 
>
>
>Hi
>
>I am wondering if in a network we are running CR-LDP TE (for traffic
>having QoS requirements as well as BE traffic), how do we 
>account for the
>bandwidth used by best effort traffic while doing QoS path 
>computation for
>flows having QoS requirements.
>
> Do we consider bandwidth required by BE traffic as zero or we take
>average bandwidth used by BE flows into account. If we account BE LSPs
>having zero bandwidth then how accurate are the QoS path 
>computations if
>the BE flows account for a substantial portion of the network traffic.
>
>Manish
>
>