Subject: Re:Just Say No to QOS-routing in MANET

From: wkui <[email-masked]>
Date: Thu, 02 Mar 2000 23:03:50 -0600

Hi:

I think it is necessary to clarify that "Say No to QoS-Routing" is not
equivalent to "not advocating any particular QoS approach". In fact,
Andrew just proposes a method that supports QoS by using in-band
signaling together with routing protocols.

Both methods (QoS routing and signaling + routing+forwarding) have their
advantages. Does anybody want to give some comments?

Kui

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From: Joe Macker <[email-masked]>
Date: Fri, 03 Mar 2000 10:42:08 -0500

Kui:

QoS is important technical topic in general.  

I want it to be clear that we Do NOT have a scoped charter to solve QoS
mobile routing and advocate a position on that.  

There are many valid alternative approaches to QoS with associated complex
tradeoffs.

It should be clarified that it is o.k. to discuss issues and propose
approaches (these may be integrated for consideration) but in my mind this
is secondary to getting routing protocol(s) matured. Afterall , a simple,
lightweight routing protocol and something like diffserv might go a long
way in a mobile wireless environment for many application scenarios.

-Joe

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From: Qingming Ma <[email-masked]>
Date: Fri, 03 Mar 2000 12:04:12 -0800

First, QoS routing is a part of general QoS resource management. Other
parts include scheduling, traffic conditioning and resource reservation,
depending on what service model (DiffServ or IntServ) to use.

QoS routing provides a way to balance network load in order to avoid
congested spots in the network. There is no agreed approach to do
QoS routing now, although the IETF Traffic Engineering group is defining 
an Architecture for traffic engineering, within which QoS routing function
can be achieved. It seems more promising
to use MPLS based explicit routes to support QoS routing rather than 
trying to extend the existing routing protocol such as OSPF or ISIS,
although these protocols may need to extended to distribute certain
load information needed for traffic engineering.

In a cellular mobile wireless network, load balancing is still necessary
although there may not need to do QoS routing at this time before the 
bandwidth intensive applications take place. Let us keep our eyes open 
to the development of QoS routing and traffic engineering technology 
before we say yes or no to QoS routing. 

That is my 2 cents.

Qingming

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From: Ken Carlberg <[email-masked]>
Date: Fri, 03 Mar 2000 17:51:58 -0500

In principal, i agree with the points you make -- in particular, the
appeal of explicit routes.  the concern that rambles in my mind is 
the application MPLS to MANET-type networks.

part of the strength of MPLS is the expectation that edge routers are 
the entities that generate explicit routes.  thus, 'interior' routers
are not burdened with updates and hop-by-hop routing decisions, as well
as other system overhead conditions.  however, with ad-hoc networks, 
what constitutes the edge of the network with repect to hosts, is fuzzy 
at best, and likely or expected to change over time.

so maybe designs for MANET-QoS support may need to be (significantly?) 
less deterministic than that found for sesile (non-moving) networks.

cheers,

-ken