From: Muhammad Ahmed (faisal3541@hotmail.com)
Date: Tue Jun 24 2008 - 23:50:18 ART
resending the configuration with line breaks. do not know what happened
there.
class-map match-any GOLD
match access-group 105
policy-map MEX_Priority
class GOLD
priority 1544
class class-default
fair-queue
random-detect
shape average percent 93 10 ms
interface Multilink1
ip address 10.63.0.1 255.255.0.0
ip flow ingress
ip flow egress
load-interval 30
ppp multilink
ppp multilink interleave
ppp multilink group 1
ppp multilink fragment delay 1
ppp timeout multilink lost-fragment 0 200
service-policy output MEX_Priority
> From: faisal3541@hotmail.com> To: ccielab@groupstudy.com> Subject: OT - VoIP
QoS over PPP Multilink - VoIP quality issues> Date: Tue, 24 Jun 2008 21:44:24
-0500> > Hello guys,> > Sorry for the OT. I need some advise on a VoIP quality
issue over PPP> Multilink bundle. If a question sounds stupid, its probably
because it is> stupid. I do not know much about QoS and practically do not
know anything> about VoIP.> > I have configured the following on the PPP
Multilink bundle and I just want> the to ensure there is no other
configuration required to optimize VoIP> packets over the bundle.> > I am
using 3 T1's to form the bundle and PPP Multilink Multiclass is> configured on
the serial interfaces to sequence non-fragmented VoIP packets as> well. One
way delay variation between the fastest and the slowest T1 is ~8ms,> which
quite frankly I do not know if 8ms is within the jitter tolerance level> for
VoIP. End-to-end, one-way, latency between the phones is about 12ms> through
the fastest T1 and 22ms through the slowest T1. Access-list 105 is> matching
the IP addresses of the VoIP phones which have static IP addresses.> It
matches any packet destined to VoIP phones at the remote site. I am hoping>
matching VoIP phone IP addresses would match any and all VoIP packets that>
should be treated through the QoS policy. Please confirm if this would not>
match all packets. I know I should probably tag VoIP packets with DSCP or>
Precedence at the VoIP phone boundary switch but I do not manage these>
switches and I cannot convince the switch administrator to implement the>
correct configuration fast enough. fragment delay of 1 ms results in a>
fragment size of 184 bytes which I am assuming would be large enough to frame>
the largest VoIP packet, please confirm. Multilink bundle is congested with>
data traffic. I do know there are packet drops, for both PPP multiclass Class>
0 and 1, which are probably causing the entire VoIP quality issue but since>
this is my first deployment of QoS I am not confident and do not feel like I>
have the command on it to definitively say that my configuration is correct>
for QoS so I can start looking at resolving the drop packet issue with>
whichever T1 is at fault. The total VoIP payload through the bundle is>
~800kbytes during peak usage. I configured 1.544Mbps for no apparent reason>
other than to avoid built in policing on the priority policy.> > Best Regards
and thanks for reading my misery. :)> Muhammad> > BTW, the QoS policy has been
removed for testing the T1's for faults so I> would not be able to provide any
"show" command outputs.> > class-map match-any GOLD match access-group 105>
policy-map MEX_Priority class GOLD priority 1544 class class-default>
fair-queue random-detect shape average percent 93 10 ms> interface Multilink1
ip address a.b.c.d 255.255.0.0 ip flow ingress ip flow> egress load-interval
30 ppp multilink ppp multilink interleave ppp multilink> group 1 ppp multilink
fragment delay 1 ppp timeout multilink lost-fragment 0> 200 service-policy
output MEX_Priority> > > >
This archive was generated by hypermail 2.1.4 : Tue Jul 01 2008 - 06:23:23 ART