Kristjan. The main points fo QoS are this:
1. Mark as close to the edge as possible. 2. In the case of cisco devices we trust as follows: - Trust DSCP from APs (edge L3 notice they are typically on access ports themselves). - Trust CoS on controllers from the switch itself (notice it is a trunk and L2) So far we have CoS = L2 and DSCP = L3 - In between switches we have trust boundaries so we may or may not need to set up CoS to DSCP or DSCP to CoS or re-mark traffic, but if we do it will be between the switches like the 6500 and the 3750 for example. You can view the Mutation Maps on each device, copy them to notepad if needed, and then configure your mutation map accordingly. - Sometimes in a CCIE Lab we might be asked to "remark traffic" or assign a different value or even apply SRR/WRR values to the port in question. In these questions, we normally just do precisely what is asked. - As for Platinum, Gold, Silver, and Copper - Basically 4 service policies. The trick is to review these policies in the Enterprise Mobility Guide. Apply as required by the requirements of the lab. - You may be asked to police as certain value so you'd take a look at the requirements and ask yourself whether it is a policer or a shaper and then on what condition should it either drop, apply a policy, or allow to continue. You'd set the policy action in global mode on the switch. - The 6500 is fun, you see each blade model of the 6500 switch has different QoS capabilities, so it assumes you have knowledge of how to find these values - say in the QoS SRND or in the hardware configuration guide of the CCO documentation. - The MQC and Priority Queueing are assumed knowledge. - Creating access-list of one sort or another is also an assumed skillset for QoS. Imagine marking on packet size or fragments for example. Interesting? Very possible. How big did we we say VoIP packets are? - Interleaving and Fragmentation is also fun and probably fair game in the lab as well. I'd use it if I were a proctor, since it is commonly misunderstood. - Don't forget to enable QoS and then to apply it to your intefaces as required. Simply enabling QoS and nothing more actually re-marks packets to a value of 0 and that is probably not what will ever be intended in any CCIE Lab. - Agreed? You can do flips with QoS. Diagram 5-1 in the Enterprise Mobility Guide version 4.1 kind of illustrates most of my points in one single visual representation. Radio Upstram and Downstream / Network Upstream and Downsteam are valuable considerations in figuring out which way to apply QoS. Table 5.2 Explains Precedence / 802.1P The last paragraph on page 5-17 is very important and needs to be well understood. Take a look at Diagram 5-22 for a spot check on where various QoS boundaries are set in a CUWN. Here's a config for the AP for example trusting DSCP: int g1/0/1 spanning-tree portfase sw m a sw a v 10 mls qos trust dscp Another example for the WLC interface of the switch: interface GigabitEthernet1/0/13 switchport trunk encapsulation dot1q switchport trunk allowed vlan 11-13,60,61 switchport mode trunk mls qos trust cos Hope this helps a little. The diagrams I referred to should help as to where to apply QoS. QoS is really brief in the guide by comparison of a more mature understanding of the topic and make no mention of how to test QoS either to verify that you are applying the policy and getting the results you want to see. Darby 2010/11/1 Kristján Ólafur Eðvarðsson <[email protected]> > Hi guys, awfully quiet here last days :) > > I am working on QOS now. I sense that it is > essential to learn all mappings between wifi client site 802.11e to AP DSCP > and WLC COS markings. > Know what happens for a packet when marked with the Platinum profiles in > WLC and when it ends > on the upstream to client. And vice versa. Jeromes Videos are very good and > help you to understand that. > But it is essential in my mind to know all DSCP and COS mappings back and > forth. > > It is very well explained how the marking is done and controlled in the > Wireless consept. > > There is one thing bugging me. I need to have a end-to-end configuration > including the switches part. > I know about the trust DSCP from APS and trust COS from WLC's. And the COS > to DSCP markings and back. > > I saw this document in the dropbox called qos-wlc-lap.pdf which is rather > good. And all > the documents from that folder ConfigurationGuideexamples folder on > Dropbox. > > But that document only gives weigted round robin QOS method that doesn't > seem to be supported on 3560 > or 3750 I am using in my own lab. > > Has anyone a good end-to-end configuration with L2 switches, L3 switches, > WLCs, LAPs and Aps ? > with say some prioritation for voice traffic for example ? > > Somebody want to share their strong points !? > > regards. Kristjan > _______________________________________________ > For more information regarding industry leading CCIE Lab training, please > visit www.ipexpert.com > -- Darby Weaver Network Engineer [email protected]
_______________________________________________ For more information regarding industry leading CCIE Lab training, please visit www.ipexpert.com
