Can anyone point me to some sample Cisco QoS configurations suitable for IAX2? I've looked through Cisco's site, and get overwhelmed with the level of documentation (too much of a good thing). My PSTN gateway and PBX (both *) are connected via 2xT1 (per-packet load balancing) between a Cisco 7206 and a 3640. When the total bandwidth pushes much past 50%, I start getting some crazy distrotion (jitter?), making it impossible for one or both parties to understand the other. TIA, -- Troy Settle Pulaski Networks http://www.psknet.com 866.477.5638
Are you in control of both sides? What routing protocols are you using? Simply using Cisco CAR can help, but not a total solution. Are the 2 T1's carried by an ISP? Or are these private T's? -----Original Message----- From: asterisk-users-admin@lists.digium.com [mailto:asterisk-users-admin@lists.digium.com] On Behalf Of Troy Settle Sent: Monday, April 05, 2004 11:49 AM To: asterisk-users@lists.digium.com Subject: [Asterisk-Users] Cisco QoS Howto Can anyone point me to some sample Cisco QoS configurations suitable for IAX2? I've looked through Cisco's site, and get overwhelmed with the level of documentation (too much of a good thing). My PSTN gateway and PBX (both *) are connected via 2xT1 (per-packet load balancing) between a Cisco 7206 and a 3640. When the total bandwidth pushes much past 50%, I start getting some crazy distrotion (jitter?), making it impossible for one or both parties to understand the other. TIA, -- Troy Settle Pulaski Networks http://www.psknet.com 866.477.5638 _______________________________________________ Asterisk-Users mailing list Asterisk-Users@lists.digium.com http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Hi Troy, Troy Settle wrote:>Can anyone point me to some sample Cisco QoS configurations suitable for >IAX2? I've looked through Cisco's site, and get overwhelmed with the level >of documentation (too much of a good thing). > >Take a look at this and see if you can use it for IAX2 as well: http://www.cisco.com/univercd/cc/td/doc/product/rtrmgmt/qos/qpm21/qpm21ug/ugvoip.htm [ snip ] HTH, Martin
You can also take a look at the following URL: <http://www.cisco.com/en/US/products/sw/iosswrel/ps1835/products_command_ref erence_chapter09186a0080087f26.html> -----Original Message----- From: asterisk-users-admin@lists.digium.com [mailto:asterisk-users-admin@lists.digium.com] On Behalf Of Troy Settle Sent: Monday, April 05, 2004 11:49 AM To: asterisk-users@lists.digium.com Subject: [Asterisk-Users] Cisco QoS Howto Can anyone point me to some sample Cisco QoS configurations suitable for IAX2? I've looked through Cisco's site, and get overwhelmed with the level of documentation (too much of a good thing). My PSTN gateway and PBX (both *) are connected via 2xT1 (per-packet load balancing) between a Cisco 7206 and a 3640. When the total bandwidth pushes much past 50%, I start getting some crazy distrotion (jitter?), making it impossible for one or both parties to understand the other. TIA, -- Troy Settle Pulaski Networks http://www.psknet.com 866.477.5638 _______________________________________________ Asterisk-Users mailing list Asterisk-Users@lists.digium.com http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
> Can anyone point me to some sample Cisco QoS configurations suitable for > IAX2? I've looked through Cisco's site, and get overwhelmed with the level > of documentation (too much of a good thing). > > My PSTN gateway and PBX (both *) are connected via 2xT1 (per-packet load > balancing) between a Cisco 7206 and a 3640. When the total bandwidth > pushes much past 50%, I start getting some crazy distrotion (jitter?), > making it impossible for one or both parties to understand the other.There are several different ways to do it, some with better results then others, and most highly dependent up specific IOS versions, etc. Here's one way based on a policy map: In iax.conf, tos=lowdelay (Note: that sets the TOS bits in the IP header. If you're not familiar with that, use a packet sniffer to check it out.) If you want to mess with sip, then in sip.conf set tos=0x18 ;lowdelay ;sets ip tos bits (=lowdelay and throughput) In the Cisco, use the following: 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 80 class www-traffic bandwidth 80 class class-default fair-queue Interface <whatever your outbound is> service-policy output voice-policy 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 The above policy map essentially places any packets matching access list 103 in the "priority" queue, while packets matching 105 are placed in the next lower queue. All other protocols/ports/etc fall into the "default" queue. Pay close attention to those words in the above statements. If I recall correctly, you can have up to something like eight queues. When its functional, then do: show policy-map int <whatever your interface is> to see how many packets fell into each queue. Adjust the "priority 80" and "bandwidth 80" statements to influence the amount of bandwidth allocated to each queue. The 80 represents 80,000 bits/second, the total does not have to add up to your actual circuit bandwidth. Its an "influence", not a fixed value. The approach only addresses outbound packets, not inbound. To address the in-bound traffic one has to go to the opposite end of the link and set the same type of config. The above has no impact on packets flowing through ISP routers (or anyone else's routers) for which you do not have control and an equivalent policy map. The above works fine on v12.2(4)T7, however you'll want to check to see which exact versions actually support policy maps, etc. As I'm sure others will point out, there are lots of other considerations to engineering this including switches, etc, etc. Rich