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<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Thanks Jason.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>After doing some more research I think I may
be hitting CSCsb49202:<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>6608 : Incorrect marking DSCP value to 0<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>It is first fixed in version 4.1(3)ES53
which is newer than SR3c which is what we’re running and is the latest SR.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>If this is the problem this actually makes
sense. I’m not seeing any drops in the HIGH priority queue, but
plenty in the low queue when there is congestion on the T1. All of the
RTP packets I saw were marked EF, but I didn’t see if every single packet
in sequence was marked with EF. If some are being marked with DSCP 0 then
they would be dropped in the low priority queue which I see plenty of drops
there when there is congestion on the T1. And the fact that if I am on an
internal call (over the T1) or out a different gateway I do not see any
problems.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>PQ has been working fine for us and works
fine with links over satellite for oil rigs. We only care about voice so
that’s why we use legacy PQ. Easy and straightforward.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Instead of upgrading to the latest ES we’re
going to mark all RTP packets with DSCP EF manually to make sure they are
marked properly. I will update the group with the results.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><br>
Thanks for all of the input!<br>
<br>
Keith<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
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<p class=MsoNormal><b><font size=2 face=Tahoma><span style='font-size:10.0pt;
font-family:Tahoma;font-weight:bold'>From:</span></font></b><font size=2
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'>
cisco-voip-bounces@puck.nether.net [mailto:cisco-voip-bounces@puck.nether.net] <b><span
style='font-weight:bold'>On Behalf Of </span></b>Jason Aarons (US)<br>
<b><span style='font-weight:bold'>Sent:</span></b> Wednesday, October 25, 2006
11:54 AM<br>
<b><span style='font-weight:bold'>To:</span></b> cisco-voip@puck.nether.net<br>
<b><span style='font-weight:bold'>Subject:</span></b> Re: [cisco-voip] Strict
Priority Queuing over T1 for Voice</span></font><o:p></o:p></p>
</div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>I would change the QoS match the Cisco
SRND recommendations. Plus Cisco can’t say your are not using their best
practices.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>It seems to me you get more deatail in
show policy-map interface versus show queueing interface.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Aside from that look for show queueing
interface, show interface and drops. You indicate none are found, maybe verify
that with Ethereal/WireShark. The Smart Decode in Ethereal is pretty good.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
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<p class=MsoNormal><b><font size=2 face=Tahoma><span style='font-size:10.0pt;
font-family:Tahoma;font-weight:bold'>From:</span></font></b><font size=2
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'> Keith Klevenski
[mailto:keith.klevenski@rig.net] <br>
<b><span style='font-weight:bold'>Sent:</span></b> Wednesday, October 25, 2006
10:36 AM<br>
<b><span style='font-weight:bold'>To:</span></b> Jason Aarons (US);
cisco-voip@puck.nether.net<br>
<b><span style='font-weight:bold'>Subject:</span></b> RE: [cisco-voip] Strict
Priority Queuing over T1 for Voice</span></font><o:p></o:p></p>
</div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Just using plain old legacy priority
queuing:<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>priority-list 1 protocol ip high list 110<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>priority-list 1 protocol ip medium list
111<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>priority-list 1 protocol ip normal list
112<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>priority-list 1 default low<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>access-list 110 permit ip any any dscp ef<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>access-list 111 permit ip any any dscp
af31<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>access-list 111 permit ip any any dscp
af21<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>access-list 111 permit ip any any dscp
af22<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>access-list 111 permit ip any any dscp
af23<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>access-list 111 permit ip any any dscp cs3<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>access-list 112 permit ip any any dscp
af11<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>access-list 112 permit ip any any dscp
af12<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>access-list 112 permit ip any any dscp
af13<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<div>
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<hr size=2 width="100%" align=center tabindex=-1>
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<p class=MsoNormal><b><font size=2 face=Tahoma><span style='font-size:10.0pt;
font-family:Tahoma;font-weight:bold'>From:</span></font></b><font size=2
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'>
cisco-voip-bounces@puck.nether.net [mailto:cisco-voip-bounces@puck.nether.net] <b><span
style='font-weight:bold'>On Behalf Of </span></b>Jason Aarons (US)<br>
<b><span style='font-weight:bold'>Sent:</span></b> Wednesday, October 25, 2006
8:08 AM<br>
<b><span style='font-weight:bold'>To:</span></b> cisco-voip@puck.nether.net<br>
<b><span style='font-weight:bold'>Subject:</span></b> Re: [cisco-voip] Strict
Priority Queuing over T1 for Voice</span></font><o:p></o:p></p>
</div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Auto qos voip does a great job of
generating the policy-maps. What does your policy look like?.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>What does your show policy-map interface
x/y/z show when the problem occurs? Are LLQ matched packets being
discarded? Maybe the service-policy is not protecting the voice like you think.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<div>
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face="Times New Roman"><span style='font-size:12.0pt'>
<hr size=2 width="100%" align=center tabindex=-1>
</span></font></div>
<p class=MsoNormal><b><font size=2 face=Tahoma><span style='font-size:10.0pt;
font-family:Tahoma;font-weight:bold'>From:</span></font></b><font size=2
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'>
cisco-voip-bounces@puck.nether.net [mailto:cisco-voip-bounces@puck.nether.net] <b><span
style='font-weight:bold'>On Behalf Of </span></b>Keith Klevenski<br>
<b><span style='font-weight:bold'>Sent:</span></b> Tuesday, October 24, 2006
5:43 PM<br>
<b><span style='font-weight:bold'>To:</span></b> cisco-voip@puck.nether.net<br>
<b><span style='font-weight:bold'>Subject:</span></b> [cisco-voip] Strict
Priority Queuing over T1 for Voice</span></font><o:p></o:p></p>
</div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Hi all,<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>I’ve been battling a problem that seemed to have
surfaced recently as we have added more users to the office. We have an
office of about 35 users now with a point to point T1 (HDLC) between this
office and the datacenter where the CallManager’s (running 4.1.3) and
PSTN gateway (6608 blade) are. Basically this:<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>PSTN<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'> |<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>6608/6509 (datacenter) (12.1(11b)E14 on msfc and 6.4(10) on
sup)<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'> | trunk<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>7200 (datacenter) 12.3(6a)<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'> |<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>T1<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'> |<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>2811 (remote office) 12.3(11)T7<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'> | trunk<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>3750 (remote office)<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'> |<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Phones<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>We have strict priority queuing configured on the T1
interfaces (and the FastEthernet interfaces although I don’t think this
is necessary) with DSCP EF traffic in the high queue and signaling
(AF31/21/22/23 and CS3) the medium queue and other traffic in the normal and
low queues. <o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>The problem is when the T1 is saturated we start seeing high
jitter (1-2 seconds) and rxlost packets on the phones and voice quality of
course suffers. The thing is I see NO dropped packets on any interface
from the PSTN to the switch port the phone is connected to other than the call
statistics on the phone. This confuses me greatly unless the phone itself
is dropping them… it would seem that if the phone determines there are
missing packets (rxlost) they would show up on some interface somewhere but
they do not. Sniffer traces at the phone show the missing packets.
Sniffer traces at the trunk at the remote office show missing packets, but
traces on the trunk in the datacenter (from the 7200 to 6509) show all packets
accounted for. Seems like the T1 is the issue. There are 24 line
code violations on the T1 in the last 24 hours, but no slips. The problem
only seems to occur when there is high traffic on the T1. We also noticed
no other traffic is marked EF and the RTP stream is EF at the datacenter and at
the office so that isn’t being remarked or anything. But there are
no input queue drops on the 2811 (which I wouldn’t expect since the RTP
stream should be CEF switched anyway). If the input interface cannot
handle the amount of traffic and the traffic is all CEF switched where would
you see input drops? There are a handful of buffer failures, but nothing
that would account for the number of complaints I’ve been getting lately.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>I’ve connected my phone directly to the 2811 and
bypassed the 3750 with the same results.<br>
<br>
I also noticed that the rxsize fluctuates between 10ms and 20ms also.
Shouldn’t that always be 20ms? I thought that was odd.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>I guess my main question is when using strict priority
queuing shouldn’t the voice packets ALWAYS get sent first no matter
what?? I want to believe they are since there are NO drops in the high
priority queue outbound from the datacenter. What is the best way to do
QoS for voice over a T1 when you only care about the voice? Seems like
strict priority queuing is the best way to assure voice traffic is sent
first. We don’t really care about starving out any other
traffic. If packets are being dropped shouldn’t I see them
somewhere other than on the phone?<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Any input on this problem is welcome!<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
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