Whether it is CBWFQ or WFQ,  the sheduling is based on the weight value , the sheduler prefer lowest weight and it takes the packet with lowest weight from software queue and move in to hardware queue Let say we have CBWFQ configured on interface and fair queue configured under class-default the sheduler will takes the the packet with lowest weight from the queue 2^n + 7     wieht = 1024                                                              this is for link quue for traffic like routing 2^n + 8     weight = 0                                                                  This is for Priority queue >2^n + 8   weight = const*interface BW/class-map Bandwidth        User defined class maps 2^n           weight = 32384/(IPP +1)                                              this is  WFQ and all the queues are dynamically assign So the strange thing i observed is if we configured user-defined class with bandwidth 3% and remaing allocated to the class default with fair queue * user-defined class is still allocated with more bandwidth then the class-default with fair queue to summarise on my understanding To summarize what we learned so far: 1) CBWFQ is nothing else than WFQ on steroids 2) User-defined classes have much better scheduling weights than any dynamic flow queue. Therefore, the bandwidth allocated to dynamic queue usually is small compared to any user-defined class. 3) Scheduler shares interface bandwidth in relative proportions. For example, if you have two classes configured with bandwidth values of “32” and “64” and interface bandwidth 128 that does not mean system will allocate classes 32Kbps and 64Kbps. That means: in case on congestion CBWFQ will share bandwidth in proportions 32:64=1:2 between the two classes, plus some small amount to class-default. If you want bandwidth to be “realistic”, ensure your entire bandwidth values sum to interface bandwidth. The same goes to bandwidth percents. 4) If you want the scheduler to honor class-default traffic, assign it an explicit bandwidth value. This will effectively disable dynamic flow queues (though preserve Link Queues) and assign all unclassified traffic to a single FIFO queue. Info taken from http://blog.ine.com/2008/08/17/insights-on-cbwfq/ ... View more

Hi i have a question in qos how the router treats the packet with the dscp values when no action configured for marking , for example if router recieves the packet marked with AF11 and cs2 which packet gets better treatment . is it based on the order of the dscp value AF11(dscp 10) CS2 (dscp 16) ??? when and what case  CS values used in real time ?? ... View more

Sorry last Post was bit messy this is my design [CoreSw]--->MT-RJ--->SC-------->[PatchPannel]---------------------------------------->[Patch Pannel]------------>SC--------->LC----------[Edge Switch] ... View more

Hi Tom, Thank you very much for your prompt reply, finally i understand.As my cable distance is with in 2Km iam ok with MMF Secondly i dont't want to use any media convertor in between the Core Switch and Edge Switch Can i design my uplinks in the following way is it correct? (Using MMF) CoreSwitch -> MT-RJ---->SC----->[PatchPanne]l------------------------------------------------------------->[PatchPannel]----->SC-----> LC------->[Edge-Switch] (3750 100Mbps)                      (Near CoreSwitch)                                                               (Near Edge)                                 (2960 100Mbps SFP) Is 100Mbps SFP  MMF is available for 2960? Regards Deva ... View more