Re: WRED and QoS provisioning in ISP network

[James <haesu () towardex com>]

On Tue, Aug 31, 2004 at 07:27:58PM +0800, Joe Shen wrote:
>  Hi,
>
> We are evaluting whether we should implement DiffServ
> Based e2e QoS provisioning in our network. Someone
> recommend that WRED should be used on each node which
> is setup to send traffic according to
> DSCP/IP_precedence. They disclame that DiffServ+WRED
> is the best solution for current network. But, as I
> know WRED will bias normal TCP flows, while UDP and
> greedy TCP flows(like BT download) will win in
> Bandwidth competition.

x/RED in general is pretty useless in reality for most service providers in my
opinion. It takes a lot of tweakings to get it to optimal ofcourse and its only
efficient in overall TCP and/or congestion managed flows that can back off/drop
down during signs of congestion through packet drop.

On the same token however, RED is probably useful for certain edge routers, on
customer serial interfaces. But again, dependent on the type of traffic customer
does, etc.

 
> Is there anybody could do some help on telling me:
>
> 1. Is there any ISP use WRED in there network and gain
> much from it? How do they use it ?
>
> 2. Is there any information available on how ISP plan
> their network according DiffServ architecture?
>
> 3. Is there any tool to monitor bandwidth utilization
> of each QoS class on each node ? Is there any tool to
> monitor e2e QoS performance of each QoS class?
>
> 4. How does they plan trunk capacity in a dynamic
> network environment? esp. in DiffServ network
>
> 5. Is there any possible security problem in a QoS
> enabled network?
>
> 6. How could we optimize network architecutre
> according to QoS policy? 
>
> Each word will be highly appreciated.
>
> Joe Shen
>
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-- 
James Jun                                            TowardEX Technologies, Inc.
Technical Lead                        Network Design, Consulting, IT Outsourcing
james () towardex com                  Boston-based Colocation & Bandwidth Services
cell: 1(978)-394-2867           web: http://www.towardex.com , noc: www.twdx.net