Thats right, and to be more precise, it matches every RTP+UDP packet in that
range, by default Cisco and almost all vendors use RTP even ports (and RTCP
odd ports)

What I mean is that "match ip rtp 16384 16383" does not match every UDP even
port, but every RTP+UDP port.

//r.a.

On Fri, Dec 17, 2010 at 8:24 AM, Nicolas MICHEL <[email protected]>wrote:

> Thanks Ricardo for the explanation it makes sense now.
>
>
> however, I agree for the ACL range but what about the command
>
>
> match ip rtp 16384 16383 . it matches every even number in the RTP UDP
> range 16384 32767 right ?
>
>
> Thanks
>
>
>
>
> But the example are match ip
>
> 2010/12/17 Ricardo <[email protected]>
>
>  Nicolas,
>>
>> When working with ranges in a class map definition we define the starting
>> port number and the range of ports, ie 16384 as staring port and 16383 more
>> ports, that is up to port 32767.
>>
>> When using ACL we define a range: ie starting and ending port.
>>
>> Moreover when we work with ACL we define ANY traffic using UDP and with
>> class-maps only the RTP using UDP ports.
>>
>> To talk about something deeper however is that a good thing of ACL though
>> is that we have included RTCP (odd even port numbers) as well, not in the
>> class map matching RTP Only.
>>
>> //r.a.
>>
>>   On Fri, Dec 17, 2010 at 6:25 AM, Nicolas MICHEL 
>> <[email protected]>wrote:
>>
>>>  Hey there guys!
>>>
>>> I'm actually reading Cisco QoS Book from Wendell Odom and something is
>>> interesting here.
>>>
>>> They are using class-map like this to match ALL RTP traffic
>>>
>>> class-map RTP
>>> match ip rtp 16384 16383
>>>
>>>
>>> Isn't that weird ? In most document I see that they use an ACL that match
>>> UDP 16384 to 32767 .
>>>
>>>
>>> Can someone have some hints about this ?
>>>
>>>
>>> many thanks for the help provided.
>>>
>>>
>>>
>>> Nicolas
>>> _______________________________________________
>>> For more information regarding industry leading CCIE Lab training, please
>>> visit www.ipexpert.com
>>>
>>
>>
>
>
> --
> Nicolas MICHEL
> Ingenieur Réseaux et Securité (CCNA/CCNP)
>
>
>
>
>
_______________________________________________
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