I found this command if your Cisco switches support it: "auto qos voip trust" You set this on each interface. It automatically prioritizes all SIP and skinny traffic, but not iax.
There is also "auto qos voip cisco-phone". This one can detect a Cisco phone and prioritize it. I just have to figure out how to verify that it is actually doing anything. -- -- Steven http://www.glimasoutheast.org "Rich Adamson" <[EMAIL PROTECTED]> wrote in message news:[EMAIL PROTECTED] > Nick Hoffman wrote: >> On Sat September 23 2006 06:14, Bob Amen <[EMAIL PROTECTED]> wrote: >> <snip> >>> which sets the TOS bit on all IAX, SIP and RTP packets. Using iptables >>> means that we can set up our rules on the router without using ACLs. Our >>> Cisco Cookbook (http://www.oreilly.com/catalog/ciscockbk/) has a nice >>> section on QoS (Chapter 11) and an appendix on TOS, etc. The author >>> advises not to use ACLs when possible as they take more CPU in the >>> router to implement and on a heavily loaded router can cause packet >>> delays. So here's what our config looks like: >> <snip> >>> Cheers, >>> Bob >> >> >> Hi Bob. I'm new to TOS and DSCP, but after going over your and Rich >> Adamson's responses to Steve BerkHolz's question, I read up >> about them. >> >> With what you wrote above, does this mean that your Cisco router(s) deny, >> allow, and route traffic based on TOS/DSCP flags, and >> you don't bother with traditional ACL rules like below?: >> access-list 123 permit udp 1.2.3.4 ... > > ACL's in cisco hardware can be used for pattern matching in addition to the > old permit, deny, etc, functions. > > Here's a working example from a cisco 1750 with QoS: > > class-map match-all voice-rtp > match access-group 103 > class-map match-all www-traffic > match access-group 105 > ! > ! > policy-map voice-policy > class voice-rtp > priority percent 40 > class www-traffic > bandwidth percent 30 > class class-default > fair-queue > > access-list 103 permit ip any any dscp cs3 > access-list 103 permit ip any any dscp ef > access-list 103 permit ip any any tos min-delay > access-list 103 permit ip any any tos 12 > access-list 105 permit tcp any eq www any > > In the above, any packet matching the access-list 103 gets treated as a > "voice-rtp" class, and in the policy map, is acted upon as > "priority" (which means low latency queue) and can use up to 40% of the > interfaces bandwidth. > > The "bandwidth 384" statement on the interface "is" used by QoS to determine > how much is actually going to be used for voip. > > interface Dialer0 > bandwidth 384 > ip address negotiated > encapsulation ppp > dialer pool 1 > dialer-group 1 > service-policy output voice-policy > ppp pap sent-username xxxxx_dsl password 7 136775499987 > > That bandwidth statement should be the "actual" amount of bandwidth available > and not the value that your dsl/broadband provider > says they provide. > > Once the policy map is implemented, one can review the operational statistics > by doing something like this: > C1750#show policy-map interface dialer0 > Dialer0 > > Service-policy output: voice-policy > > Class-map: voice-rtp (match-all) > 1441504 packets, 191386680 bytes > 5 minute offered rate 0 bps, drop rate 0 bps > Match: access-group 103 > Weighted Fair Queueing > Strict Priority > Output Queue: Conversation 136 > Bandwidth 40 (%) > Bandwidth 153 (kbps) Burst 3825 (Bytes) > (pkts matched/bytes matched) 0/0 > (total drops/bytes drops) 0/0 > > Class-map: www-traffic (match-all) > 484061 packets, 341420115 bytes > 5 minute offered rate 0 bps, drop rate 0 bps > Match: access-group 105 > Weighted Fair Queueing > Output Queue: Conversation 137 > Bandwidth 30 (%) > > Also, by doing the following: > C1750#show access-list 103 > Extended IP access list 103 > permit ip any any dscp cs3 > permit ip any any dscp ef (1680 matches) > permit ip any any tos min-delay (808709 matches) > permit ip any any tos 12 (1 match) > > one can "see" which piece of an access list is being matched. One can also > see that both TOS and DSCP definitions can be used > within the same access list. Its kind of a handy way to ensure voip phones > and asterisk are properly configure and thus properly > treated from a QoS perspective. > > It should also be noted the above router is running v 12.2(4)T7 code. Cisco > has made several changes to the syntax and parameters > implemented in each version in the last few years. In the newer IOS versions > (for both switches and routers), the syntax and > parameters are becoming much more standardized across all product lines. > > The OP was specifically asking about QoS on a cisco switch, and without > researching exactly what was implemented in "his" switch, > there really isn't any way to give him a QoS template that would be accurate. > For example, if I posted something that worked in > the 12.4 code, its highly likely not to be acceptable syntax for 12.1 or 12.2. > > Whether one uses access lists to do pattern matching is mostly immaterial > "except" on a heavily loaded router. In my case, the > processor utilization looks like: > C1750#show proc > CPU utilization for five seconds: 1%/0%; one minute: 1%; five minutes: 1% > > where lengthy access lists would have almost zero impact. > > For those that have read this far, it should be noted the implementation is a > 3-queue policy (one for rtp, one for www, and one as > the default). If the traffic for the rtp queue is low (or none), the unused > bandwidth is automatically made available to other > lower priority queues. In other words, the allocation of bandwidth to the > various queues only occurs when demand is greater then > the bandwidth available. Also, QoS can only be applied to "outbound" > interfaces; inbound QoS must be done at the isp. > > Rich > > _______________________________________________ > --Bandwidth and Colocation provided by Easynews.com -- > > asterisk-users mailing list > To UNSUBSCRIBE or update options visit: > http://lists.digium.com/mailman/listinfo/asterisk-users > _______________________________________________ --Bandwidth and Colocation provided by Easynews.com -- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
