The MPLS WG Archive

[Prosenjit Pal <ppal@allegronetworks.com>]

Title: RE: A question

Hi Nasser,

    Please refer to the following documents:
1. RFC2474
2. RFC2597
3. RFC2598
4. http://www.ietf.org/internet-drafts/draft-ietf-mpls-diff-ext-06.txt

    Among 64 possible codepoints there are categories:

1. 64 possible DSCPs are classified into 3 pools : 32 of them
(xxxxx0) are in Standards Action pool.
2. Among those 32 values, 8 of them (xxx000) are defined as
Class Selector Code Points.
3. Some of the DSCPs are clubbed to form a group of PHB like
Assured Forwarding PHB group.

   Again mapping DSCPs to EXP field can be either through
configuration or through signaling. Depending on the type of
LSP (i.e. L-LSP or E-LSP), EXP field can indicate scheduling
treatment and/or drop precedence. Again these mappings can
differ from one diff-serv domain to another.

Hope it helps.

Thanks,
Prosenjit Pal

-----Original Message-----
From: Nasser Yazdani
To: MPLS
Sent: 7/25/00 7:29 AM
Subject: A question

Hi,

does anybody knows how to map the DiffServ classes (64 classes) into the
MPLS exp. fields (8 classes). Thanks,

Regards,

-- Nasser