It didn't used to. Now the last time I looked at the actual functionality down to that level was years ago to dive into programming stuff... But AFAIK that mechanism hasn't changed. Remember that if there's no congestion you aren't actually queuing, so you should not have any starvation problems! Scott
_____ From: Ralph Olsen [mailto:[EMAIL PROTECTED] Sent: Monday, February 18, 2008 1:48 PM To: [EMAIL PROTECTED]; 'Victor Cappuccio'; 'Derek Winchester' Cc: [email protected] Subject: SV: [OSL | CCIE_RS] Shape vs Police question Hi Scott, Doesnt the priority police at all times to avoid starvation? /Ralph Fra: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] På vegne af Scott Morris Sendt: 18. februar 2008 01:36 Til: 'Victor Cappuccio'; 'Derek Winchester' Cc: [email protected] Emne: Re: [OSL | CCIE_RS] Shape vs Police question The "priority" keyword only polices during times of congestion. but yes, that is an added feature as well! Scott Morris, CCIE4 (R&S/ISP-Dial/Security/Service Provider) #4713, JNCIE-M #153, JNCIS-ER, CISSP, et al. CCSI/JNCI-M/JNCI-ER VP - Technical Training - IPexpert, Inc. IPexpert Sr. Technical Instructor A Cisco Learning Partner - We Accept Learning Credits! [EMAIL PROTECTED] Telephone: +1.810.326.1444 Fax: +1.810.454.0130 http://www.ipexpert.com _____ From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Victor Cappuccio Sent: Sunday, February 17, 2008 6:50 PM To: Derek Winchester Cc: [email protected] Subject: Re: [OSL | CCIE_RS] Shape vs Police question LLQ when the traffic exceed the configured Priority it gets dropped R1#conf ter Enter configuration commands, one per line. End with CNTL/Z. R1(config)#access-list 101 permit ip any any pre 3 R1(config)#class-map TEST R1(config-cmap)#ma access-gr 101 R1(config-cmap)#exit R1(config)#policy-map TEST R1(config-pmap)#class TEST R1(config-pmap-c)#prio 250 R1(config-pmap-c)#exit R1(config-pmap)#int s1/1 R1(config-if)#serv out TEST R1(config-if)#do show policy-map int s1/1 Serial1/1 Service-policy output: TEST Class-map: TEST (match-all) 0 packets, 0 bytes 5 minute offered rate 0 bps, drop rate 0 bps Match: access-group 101 Queueing Strict Priority Output Queue: Conversation 264 Bandwidth 250 (kbps) Burst 6250 (Bytes) (pkts matched/bytes matched) 0/0 (total drops/bytes drops) 0/0 Class-map: class-default (match-any) 1 packets, 84 bytes 5 minute offered rate 0 bps, drop rate 0 bps Match: any R1(config-if)# R1#ping Protocol [ip]: Target IP address: 3.3.3.3 Repeat count [5]: 10 Datagram size [100]: 1000 Timeout in seconds [2]: 0 Extended commands [n]: y Source address or interface: Type of service [0]: 0x60 Set DF bit in IP header? [no]: Validate reply data? [no]: Data pattern [0xABCD]: Loose, Strict, Record, Timestamp, Verbose[none]: Sweep range of sizes [n]: Type escape sequence to abort. Sending 10, 1000-byte ICMP Echos to 3.3.3.3, timeout is 0 seconds: .......... Success rate is 0 percent (0/10) R1#show policy-map int s1/1 Serial1/1 Service-policy output: TEST Class-map: TEST (match-all) 10 packets, 10040 bytes 5 minute offered rate 2000 bps, drop rate 2000 bps Match: access-group 101 Queueing Strict Priority Output Queue: Conversation 264 Bandwidth 250 (kbps) Burst 6250 (Bytes) (pkts matched/bytes matched) 10/10040 (total rops/bytes drops) 4/4016 Class-map: class-default (match-any) 15 packets, 1092 bytes 5 minute offered rate 0 bps, drop rate 0 bps Match: any R1# Thanks -- Victor Cappuccio www.vcappuccio.wordpress.com On Feb 18, 2008 12:44 AM, Derek Winchester <[EMAIL PROTECTED]> wrote: In regards to llq I believe that it wont limit but guarantee the bandwidth so you can spike above the configured amount if available. On 2/17/08, Victor Cappuccio <[EMAIL PROTECTED]> wrote: > > Hi Derek, > > I heard this question before, I would agree on your answer, but what about > also using, LLQ within a CBWFQ, in addition of that priority queue is > serviced with a strict priority scheduler in which I do not see any , and in > the event of congestion, if the priority queue traffic exceeds the bandwidth > guarantee, a congestion-aware policer is used to drop the exceeding traffic. > > Just a thought > Thank > > -- > Victor Cappuccio > www.vcappuccio.wordpress.com > > > On Feb 18, 2008 12:23 AM, Derek Winchester <[EMAIL PROTECTED]> > wrote: > > Someone asked me a very good question yesterday and I am still > > confused if I gave him the correct answer. He gave me a scenario that > > states that he has to limit all IP Precedence 3 traffic out of an > > interface to 256k, but he cannot use policing or rate-limiting. My > > answer was to use shaping. But from my experience, doesn't the word > > "limit" negates that as a possible answer? Even though you can use > > shaping to limit, I was always under the impression when studying for > > the CCIE that if they use the word limit that means no shaping. Can > > someone help ease my conscience? > > > > > > -- Derek S. Winchester www.myprofessorvoip.com www.winchester1.com www.derekspeaks.org
