On 5/1/13, Wes Tribble <westribble@gmail.com> wrote:
I have a question for the QOS gurus out there.
cisco-nsp might be a better place to post your question. But in any case, this option looks right:
Another Idea I had was to create a bunch of shaper classes all feeding the same child policy for priority queuing and bandwidth reservations based on DSCP markings. I’m just not exactly sure that this is allowed or supported.
see http://puck.nether.net/pipermail/cisco-nsp/2007-October/044508.html So they just shaped at the hub towards the spoke to prevent overrunning the PE-CE link at the spoke. Another advantage was they didnt' waste hub-PE bandwidth for traffic that would be dropped at the spoke PE-CE link anyway. which has nothing to do with IOS-XE but does sound like what you're wanting to do. Regards, Lee
We are having some problems with packet loss for our smaller MPLS locations. This packet loss is due to the large speed differential on our Hub site(150mb/s) in comparison the the branch office locations(single T-1 to 4.5mb/s multilinks). This packet loss only seems to impact really bursty applications like our Web Proxy. I have been around and around with WindStream to give me some extra buffer or enable random early detection on the smaller interfaces in my MPLS network. So far they are unwilling to do a custom policy and none of their standard policies have enough buffer to handle the bursts. They do FIFO tail drop in every queue, so I can’t even choose a policy that has WRED implemented.
I am looking for a way to solve the problem on my side. I can create a shaper for the proxy and match off an access-list to the smaller sites, but I am either forced to do bandwidth reservations for each site, or have multiple sites share the same shaper. Here is an example of what I was playing around with:
ip access-list extended ProxyT1Sites
permit tcp any host 10.x.x.x 10.x.x.x 0.0.0.255
permit tcp any host 10.x.x.x 10.x.x.x 0.0.0.255
class-map match-any ProxyShaperT1
match access-group name ProxyT1Sites
policy-map WindStream
class VOICE
priority percent 25
set dscp ef
class AF41
bandwidth percent 40
set dscp af41
queue-limit 1024 packets
class ProxyShaperT1
shape average 1536
bandwidth percent 1
set dscp af21
queue-limit 1024 packets
class class-default
fair-queue
set dscp af21
queue-limit 1024 packets
Another Idea I had was to create a bunch of shaper classes all feeding the same child policy for priority queuing and bandwidth reservations based on DSCP markings. I’m just not exactly sure that this is allowed or supported. I also would run out of bandwidth allocation on the policy if I use the true bandwidth number of 150mb/s. It is on a Gig port so I could just take the bandwidth statement off of the interface to give myself enough room for all of the shaper allocations.
Something like this(I am omitting the access-list that matches the branch subnet and class map for brevity):
policy-map PerSiteShaper
class FtSmith
shape average 1536
bandwidth 1536 service policy Scheduler class Dallas
shape average 4500
bandwidth 4500 service policy Scheduler class NYC
shape average 100000
bandwidth 100000 service policy Scheduler class-default service-policy Scheduler
policy-map Scheduler class VOICE
priority percent 25
set dscp ef
class AF41
bandwidth percent 40
set dscp af41
queue-limit 1024 packets
class class-default
fair-queue
set dscp af21
queue-limit 1024 packets
Just looking for some ideas that do not involve building tunnels to our remote offices. Thanks in advance,
*Wes Tribble*