Interesting, because there's a lot of material that suggests what I just said is correct. For example I have found the following excerpts from the following books:
1) In the Cisco frame relay solutions guide (Cisco Press) Chapt 19 Page 639 it says: How do LLQ and CBWFQ compare? LLQ is an extended version of CBWFQ, whereby a strict priority queue is supported for voice or other real-time delay-sensitive traffic Source: http://books.google.com/books?id=GPuhnmjxLuQC&pg=PA518&lpg=PA518&dq=LLQ+is+an+extension+of+CBWFQ&source=bl&ots=diuxNV_nVi&sig=LkKTD2QVoFcVPqhf65dZVFzevrk&hl=en&ei=qOsETqDtGIn2tgPGm8XfDQ&sa=X&oi=book_result&ct=result&resnum=3&ved=0CCYQ6AEwAjgK#v=onepage&q=LLQ&f=false 2) In the (much older) CCNP BCRAN study guide (Cisco Press) it says: Low-Latency Queuing Low-Latency Queuing (LLQ) is really just an extension of CBWFQ. In fact, the only real difference between the two is how the bandwidth is allocated to the class maps in the policy map. Source: http://www.ciscopress.com/articles/article.asp?p=102233&seqNum=5 At Wikipedia (which I know isn't always correct) it says: Low Latency Queuing (LLQ) is a feature developed by Cisco to bring strict priority queuing (PQ) to Class-Based Weighted Fair Queuing (CBWFQ). LLQ allows delay-sensitive data (such as voice) to be given preferential treatment over other traffic by letting the data to be dequeued and sent first.[1] http://en.wikipedia.org/wiki/Low_Latency_Queuing In the Cisco Frame Relay solutions guide (Cisco Press) Chapt 18 page 383 it says: With the emergence of voice traffic into data networks the need to differentiate between the various classes of service has become greater. PQ/CBWFQ, most commonly known as LLQ, is a new feature that provides a strict PQ to the CBWFQ scheme. Are all of these books wrong? Thank you, Steve Di Bias Network Engineer - Information Systems Valley Health System - Las Vegas Office - 702- 369-7594 Cell - 702-241-1801 [email protected] -----Original Message----- From: Marko Milivojevic [mailto:[email protected]] Sent: Friday, June 24, 2011 11:55 AM To: Di Bias, Steve Cc: David Swafford; [email protected] Subject: Re: [OSL | CCIE_RS] LLQ - Is it class based or it's own? No, it has nothing to do with CBWFQ. I guess it's easy to grasp the idea of it if you look at it that way though :-) -- Marko Milivojevic - CCIE #18427 Senior Technical Instructor - IPexpert FREE CCIE training: http://bit.ly/vLecture Mailto: [email protected] Telephone: +1.810.326.1444 Web: http://www.ipexpert.com/ On Fri, Jun 24, 2011 at 13:24, Di Bias, Steve <[email protected]> wrote: > Marko, isn't LLQ really just an extension of CBWFQ, called PQ/CBWFQ? I > understand it's optional; however they are still tied at the hip, no? > > > Thank you, > > Steve Di Bias > Network Engineer - Information Systems > Valley Health System - Las Vegas > Office - 702- 369-7594 > Cell - 702-241-1801 > [email protected] > > -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf Of Marko Milivojevic > Sent: Friday, June 24, 2011 8:26 AM > To: David Swafford > Cc: [email protected] > Subject: Re: [OSL | CCIE_RS] LLQ - Is it class based or it's own? > > They are different. CBWFQ (starting 12.4(20)T - HQF) and LLQ are > different queueing methods that can co-exist. They are both configured > using MQC and that gives the impression that they are somehow the same > or related, but in reality, they are not. > > LLQ queue is processed first and when that processing is done, other > classes are processed according to their requirements and the queueing > scheduler for CBWFQ/HQF. > > -- > Marko Milivojevic - CCIE #18427 > Senior Technical Instructor - IPexpert > > FREE CCIE training: http://bit.ly/vLecture > > Mailto: [email protected] > Telephone: +1.810.326.1444 > Web: http://www.ipexpert.com/ > > On Thu, Jun 23, 2011 at 13:06, David Swafford <[email protected]> wrote: >> Hi, >> >> I keep running into this question in my mind.... given a QoS >> configuration w/ a single LLQ and several CBWFQs, would the overal >> policy be consider class-based or LLQ based? >> >> Thanks, >> David. >> _______________________________________________ >> For more information regarding industry leading CCIE Lab training, please >> visit www.ipexpert.com >> >> Are you a CCNP or CCIE and looking for a job? Check out >> www.PlatinumPlacement.com >> > _______________________________________________ > For more information regarding industry leading CCIE Lab training, please > visit www.ipexpert.com > > Are you a CCNP or CCIE and looking for a job? Check out > www.PlatinumPlacement.com > > > UHS Confidentiality Notice: This e-mail message, including any attachments, > is for the sole use of the intended recipient (s) and may contain > confidential and privileged information. Any unauthorized review, use, > disclosure or distribution of this information is prohibited. If this was > sent to you in error, please notify the sender by reply e-mail and destroy > all copies of the original message. UHS Confidentiality Notice: This e-mail message, including any attachments, is for the sole use of the intended recipient (s) and may contain confidential and privileged information. Any unauthorized review, use, disclosure or distribution of this information is prohibited. If this was sent to you in error, please notify the sender by reply e-mail and destroy all copies of the original message. _______________________________________________ For more information regarding industry leading CCIE Lab training, please visit www.ipexpert.com Are you a CCNP or CCIE and looking for a job? Check out www.PlatinumPlacement.com
