From: Chris Lewis \(chrlewis\) (chrlewis@cisco.com)
Date: Thu Aug 11 2005 - 19:45:58 GMT-3
Hi,
For the case of sequential entries in a policy-map (rather than
hierarchical entries), once a packet matches a class entry in the policy
map, the set action is taken and the packet exits policy-map processing,
so EF packets will not be re-marked to anything else if they match the
top class.
The Auto-QoS-Voip-Remark only gets invoked if a packet makes it through
the policy-map without a match in any of the other classes, so for a
packet to get there it will not have matched voip-rtp or voip-control.
Regards the two entries for RTP, one matches RTP data, the other matches
RTP control packets.
From the documentation CD for the match protocol rtp command
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.
Chris
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
gladston@br.ibm.com
Sent: Thursday, August 11, 2005 11:27 AM
To: ccielab@groupstudy.com
Subject: AutoQos for Routers
Hi,
Considering the configs created by AutoQos:
class-map match-any AutoQoS-VoIP-Remark
match ip dscp ef
match ip dscp cs3
match ip dscp af31
class-map match-any AutoQoS-VoIP-Control-UnTrust
match access-group name AutoQoS-VoIP-Control
class-map match-any AutoQoS-VoIP-RTP-UnTrust
match protocol rtp audio
match access-group name AutoQoS-VoIP-RTCP
class-map match-all Select-cos
match cos 4
policy-map AutoQoS-Policy-UnTrust
class AutoQoS-VoIP-RTP-UnTrust
priority percent 70
set dscp ef <-------------------------1
class AutoQoS-VoIP-Control-UnTrust
bandwidth percent 5
set dscp af31
class AutoQoS-VoIP-Remark
set dscp default <-------------------------2
class class-default
fair-queue
ip access-list extended AutoQoS-VoIP-Control
permit tcp any any eq 1720
permit tcp any any range 11000 11999
permit udp any any eq 2427
permit tcp any any eq 2428
permit tcp any any range 2000 2002
permit udp any any eq 1719
permit udp any any eq 5060
ip access-list extended AutoQoS-VoIP-RTCP
permit udp any any range 16384 32767
I am wondering about this:
-On number 3, any packets previous marked with EF are remarked to best
effort.
-On number 2, RTP packets are marked with EF.
Suppose RTP packets enters this router with EF marked. There will be two
actions, number 2 will select/mark it with EF (which is already marked)
and number 3 will select/mark it with best effort.
That does not make sense. What am I loosing?
And, why class-map AutoQoS-VoIP-RTP-UnTrust matches the same packet two
times?
Isn't 'match protocol rtp audio' the same as "permit udp any any range
16384 32767"?
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