Subject: [NSIS] Qos-NSLP modifications related to bypassing intermediate nodes

From: "Georgios Karagiannis" <[email-masked]>
Date: Tue, 18 Oct 2005 07:44:31 +0200 (MEST)

Dear all

Regarding the GIST bypassing due to the existence of an aggregated
region, in addition to the GIST draft and extensibility draft, we will
also have to make some modifications in the QOS-NSLP draft.

It has to be specified that a signaling application, which uses the same
SESSION_ID,
may use more than one NSLP-IDs. This situation occurs when an aggregation
or a stateless
region has to be bypassed by a QoS-NSLP message.

We also have to specify that the boundary of aggregation or stateless
domains SHOULD be able to
change, for the same session, the NSLP-ID of a message that passes
through the aggregation
or stateless domain.

In particular:

Required change in Section 4.6:
-----------------------------

Change from:

"Markings are used so that intermediate routers do not need to inspect
the individual flow reservations."

INTO:
"The messages used for the signaling of the individual reservation need
to
be marked
such that the intermediate routers will not inspect them. The marking MUST
be
accomplished by the Aggregator by modifying the QoS-NSLP default NSLP-ID
value
to a NSLP-ID predefined value. The De-aggregator MUST stop this marking
process
by reassigning the QoS-NSLP default NSLP-ID value to these signaling
messages."

-----------------------------------

Required chnages in Section 4.7
-----------------------

Change from:

"At the ingress the original RESERVE message is forwarded but ignored
by the stateless or reduced-state nodes."

INTO:

"At the ingress the original RESERVE message is forwarded but ignored
by the stateless or reduced-state nodes. This is accomplished by marking
this
message, i.e., modifying the QoS-NSLP default NSLP-ID value to another
NSLP-ID
predefined value. The marking MUST be accomplished by the ingress by
modifying the QoS_NSLP default NSLP-ID value to a NSLP-ID predefined
value.
The egress MUST stop this marking process by reassigning the QoS-NSLP
default NSLP-ID value
to the original RESERVE message.
The exact operation of modifying the NSLP-ID is specified in
[I-D.ietf-nsis-rmd]."

-----------------------------------

Proposed new Section 7.3
---------------------------

"7.3. Support for bypassing intermediate nodes

The QoS NSLP may want to restrict the handling of its messages to
specific nodes. This functionality is needed to support layering
(explained in Section 3.2.8), when only the edge QNEs of a domain
process the message. This requires a mechanism at GIMPS level (which
can be invoked by the QoS NSLP) to bypass intermediates nodes between
the edges of the domain.

The intermediate nodes are bypassed using multiple levels
of the router alert option. In that case, internal routers are
configured to handle only certain levels of router alerts.
This is accomplished by marking the signaling messages, i.e., modifying
the
QoS-NSLP default NSLP-ID value to another NSLP-ID predefined value.
The marking MUST be accomplished by the ingress edge by
modifying the QoS-NSLP default NSLP-ID value to a NSLP-ID
predefined value. The egress MUST stop this marking process by reassigning
the QoS-NSLP default NSLP-ID value to the original RESERVE message.
The exact operation of modifying the NSLP-ID must be specified in the
relevant QoS model specification."
-------------------------------------------------

Do you have any objections on these proposals?

Best Regards,
Georgios

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