Re: [asterisk-users] Setting QOS settings in asterisk and/or CentOS?
BerkHolz, Steven wrote: How would I go about setting the TOS bit to RTP IP TOS Byte: 18 (hex) for SIP and IAX traffic at the asterisk server? We do it by setting the DSCP value to 40, which sets the TOS bit to 5 using iptables. Here's our rules_save for these opertations: [350334:180338667] -A OUTPUT -p udp -m udp --dport 5060 -j DSCP --set-dscp 0x28 [12085728:2417094759] -A OUTPUT -p udp -m udp --sport 1:2 -j DSCP --set-dscp 0x28 [4531:356102] -A OUTPUT -p udp -m udp --sport 4569 -j DSCP --set-dscp 0x28 [4531:356102] -A OUTPUT -p udp -m udp --dport 4569 -j DSCP --set-dscp 0x28 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: class-map match-any Class-A description Voice (IPP Critical) match ip precedence 5 match protocol rtp ! ! policy-map MPLS class Class-A bandwidth percent 25 class class-default fair-queue 512 random-detect Then you just apply the policy-map to the outgoing interface. Cheers, Bob -- Bob Amen O'Reilly Media, Inc. http://www.ora.com/ http://www.oreilly.com/ ___ --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
Re: [asterisk-users] Setting QOS settings in asterisk and/or CentOS?
BerkHolz, Steven wrote: How would I go about setting the TOS bit to RTP IP TOS Byte: 18 (hex) for SIP and IAX traffic at the asterisk server? Also, Do you have a quick reference on how to configure a Cisco switch to prioritize SIP traffic? I check in various Cisco docs, and there are so many references, and none of them seem to relate directly to using the TOS bit for QOS. I am looking into using the TOS bit because that is the only method that my SIP devices use. (Citel Handset Gateway) For asterisk, take a look at sip.conf.sample and you'll find something like this for v1.2 and earlier: tos=lowdelay;ox18 sets ip tos bits (=lowdelay, throughput) After v1.2, the look in the asterisk/docs directory and you'll find a readme file relative to QoS. The format of the QoS parameters have changed from the older TOS bits to the newer terminology Differentiated Services, and coding within sip.conf looks something like this: tos_sip=cs3 tos_audio=ef Differentiated Services is a superset of TOS; anything you want to do in TOS bits have an equivalent in Differentiated Services, and the bits map exactly. The cisco web site has a very significant amount of documentation for configuring routers and switches for QoS, and they have a very excellent 700+ page book that is oriented 100% towards implementing QoS on various cisco boxes. Cisco's search engine leaves something to be desired in some cases, but the info you want is there. Not all cisco switches have the same QoS implementations. For example, most of the workgroup type switches support something like 3 or 4 outbound queues, while the higher end switches support more queues. If you're going to deal with RTP only from a QoS perspective, you only need two queues (eg, RTP Default). The Default queue (or Class) is a special case that includes everything not in other queues. For the most part, QoS on switches is not required unless: a) trunk port traffic exceeds the bandwidth available (for that port), or, b) outbound port is a slower speed then the majority of other switch ports (eg, congestion). ___ --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
Re: [asterisk-users] Setting QOS settings in asterisk and/or CentOS?
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 ... Cheers, -- Nick e: [EMAIL PROTECTED] p: +61 7 5591 3588 f: +61 7 5591 6588 If you receive this email by mistake, please notify us and do not make any use of the email. We do not waive any privilege, confidentiality or copyright associated with it. ___ --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
Re: [asterisk-users] Setting QOS settings in asterisk and/or CentOS?
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 x_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
RE: [asterisk-users] Setting QOS settings in asterisk and/or CentOS?
Hello, For the Cisco QOS: Based on a Cisco Router all you need is a simple access-list. class-map match-any voip-class match ip rtp 10001 match access-group 150 ! ! policy-map voip-policy class voip-class priority xxx (in Kbits) access-list 150 permit udp any any eq 5060 access-list 150 permit udp any any eq 4569 Voila! Redouane De: BerkHolz, Steven [mailto:[EMAIL PROTECTED] Envoyé: jeudi 21 septembre 2006 15:33À: asterisk-users@lists.digium.comObjet: [asterisk-users] Setting QOS settings in asterisk and/or CentOS? How would I go about setting the TOS bit to "RTP IP TOS Byte: 18 (hex)" for SIP and IAX traffic at the asterisk server? Also, Do you have a quick reference on how to configure a Cisco switch to prioritize SIP traffic? I check in various Cisco docs, and there are so many references, and none of them seem to relate directly to using the TOS bit for QOS. I am looking into using the TOS bit because that is the only method that my SIP devices use. (Citel Handset Gateway) ref: QOS settings from Citel Handset Gateway: Handset Gateway - QoS Configuration IP Type of Service RTP IP TOS Byte: 18 (hex) Silence Suppression Mute Mode: On, UDP keep-alive every 10 secondsG.711 Voice Activity Detection: Off Codec Preferences G.711u: 1 (Highest priority) G.711a: 2 Thank You, Steven BerkHolz- MCSA - MCSE -Manager of Information SystemsTESCO Group CompaniesFax. 248-836-5101www.TESCOGroup.com Board member ofwww.glimasoutheast.org ___ --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
