From: Snow, Tim (timothy.snow@eds.com)
Date: Mon Jul 21 2003 - 03:01:42 GMT-3
Judging by the follow excerpt from
http://www.cisco.com/en/US/partner/products/sw/iosswrel/ps1839/products_comm
and_reference_chapter09186a008010a389.html#1076186
"It is important to note that the NBAR RTP Payload Classification feature
does not identify RTCP packets and that RTCP packets run on odd-numbered
ports while RTP packets run on even-numbered ports.The payload type field of
an RTP packet identifies the format of the RTP payload and is represented by
a number. NBAR matches RTP traffic on the basis of this field in the RTP
packet. "
I'd have to say it looks deep enough to know it's a RTP packet and not RTCP
Tim
-----Original Message-----
From: Erick Bergquist [mailto:ebergquist@ameritech.net]
Sent: Monday, July 21, 2003 1:48 AM
To: asadovnikov; 'Snow, Tim'; 'Rivalino YMT.'; ccielab@groupstudy.com
Subject: RE: Voice and Data packet in CBWFQ
Curious if anyone knows how deep the "match protocol
rtp" NBAR command looks into the packet to determine
if it is a RTP packet. Does it just look at port range
or actual payload to see if it is really RTP?
Also, for the ACLs I prefer to not use any as the
source network, and use the VoIP network subnets, etc.
This way non-voIP traffic isn't prioritized that
happens to fall in the port range.
-- asadovnikov <asadovnikov@comcast.net> wrote:
> I like this explanation.
>
> On the newer IOS you can as well use NBAR "match
> protocol rtp ..." for this
> purpose.
>
> Best regards,
> Alexei
>
> -----Original Message-----
> From: nobody@groupstudy.com
> [mailto:nobody@groupstudy.com]On Behalf Of
> Snow, Tim
> Sent: Monday, July 21, 2003 12:20 AM
> To: 'Rivalino YMT.'; ccielab@groupstudy.com
> Subject: RE: Voice and Data packet in CBWFQ
>
>
> Assuming that your voice traffic is marked with a
> precedence of 5, then yes,
> your solution will work. However, you'll also be
> putting any other traffic
> that's marked with critical in that same class.
>
> I prefer to use an ACL matching ports 16384 through
> 32767 for RTP. Keep in
> mind that will get the RTP and RTCP port numbers.
> You might also want to
> put tcp port 1720 in the "control" secion as it's
> used for h323 call setup.
>
> Tim
>
> -----Original Message-----
> From: Rivalino YMT.
> [mailto:rivel131@cyberlib.itb.ac.id]
> Sent: Monday, July 21, 2003 12:22 AM
> To: ccielab@groupstudy.com
> Subject: Voice and Data packet in CBWFQ
>
>
> Hi groups,
>
> How to match voice packet and data packet in CBWFQ?
>
> class-map VOICE
> match access-group 100
> class-map DATA
> match access-group 101
> !
> access-list 100 permit ip any any precedence
> critical
> access-list 101 ???(I have no idea)?????
>
>
> Can we use : access-list 101 deny ip any any
> precendence critical
> access-list 101 permit ip any any ?
>
> Thanks for your help,
> Rivalino
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