From: Brian McGahan (bmcgahan@internetworkexpert.com)
Date: Fri Oct 17 2003 - 18:27:43 GMT-3
Jason,
Priority queues such as the legacy priority-list, the low
latency queue (LLQ), and IP RTP priority are constantly in effect
regardless of a congestion condition. The preferred method to solve the
aforementioned problem is the LLQ.
LLQ guarantees that all packets in the priority queue are
dequeued first up to the configured bandwidth value. When packets in
the priority queue exceed the configured bandwidth and there is not
congestion, excess packets are sent but not guaranteed low latency.
When the configured bandwidth is exceeded and there is congestion,
excess packets are dropped. For this reason, the LLQ is considered a
'maximum' bandwidth guarantee. This offers a large advantage over the
legacy priority queue since your non-priority traffic cannot be starved
of bandwidth.
The IP RTP priority queue is effectively legacy because you get
the same effect by issuing the 'match protocol rtp' command in a
class-map and putting this class into the priority queue. Furthermore,
you can configure an access-list in tandem which matches ranges of UDP
ports.
Vazman, try putting the video traffic in the LLQ as suggested
and see if this helps. If not, maybe there is some trouble in the
provider cloud with your circuit.
HTH,
Brian McGahan, CCIE #8593
bmcgahan@internetworkexpert.com
Internetwork Expert, Inc.
http://www.InternetworkExpert.com
Toll Free: 877-224-8987
Direct: 708-362-1418 (Outside the US and Canada)
> -----Original Message-----
> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf
Of
> Kleberg, Jason
> Sent: Friday, October 17, 2003 6:33 AM
> To: 'Jung, Jin'; 'Vazman@aol.com'; ccielab@groupstudy.com
> Subject: RE: Videoconferencing over IP
>
> Why LLQ if there is no congestion? I think more people could help if
the
> configs were posted. And if possible, some traffic history. IS there
a
> preferred method of QOS for this?
>
> thanks
> jason
>
> -----Original Message-----
> From: Jung, Jin [mailto:jin.jung@lmco.com]
> Sent: Friday, October 17, 2003 6:25 AM
> To: 'Vazman@aol.com'; ccielab@groupstudy.com
> Subject: RE: Videoconferencing over IP
>
>
> You need some sort of QOS enabled on your T1,, I used LLQ, which seems
to
> be
> working.
>
> Also, check you frame per second fps on your Video Con unit, I know
some
> PictureTel only support 15 fps,, You need to use minium 30 fps.
>
> Jin Jung
> CCIE#12386
>
>
>
>
> -----Original Message-----
> From: Vazman@aol.com [mailto:Vazman@aol.com]
> Sent: Friday, October 17, 2003 2:05 AM
> To: ccielab@groupstudy.com
> Subject: Videoconferencing over IP
>
>
> Hello,
>
> Does anyone have any experience with using video conferencing over IP
> (point-to-point or FR). We have a T1 between two sites with a
PictureTel
> on
> each end. There is harldy any other traffic on the T1 but the quality
of
> the
> video is not soo good (jitter etc). Audio has good quality.
>
> Thanks
>
>
This archive was generated by hypermail 2.1.4 : Mon Nov 24 2003 - 07:53:04 GMT-3