Quality of Service (QoS) Explained

High level explanation of QoS

Category:

Science & Technology

Tags:

• QoS
• Cisco
• CCNA
• CCIE
• UC
• Voice
• VoIP
• Telephony

[diablorave1]

Ok this sounds great I have a question tho lets say im connected via ethernet cable to my router and there's a wireless computer connected to the router wireless and that computer is downloading, this tends to slow down my device, would (qos) ethernet port priority change that problem?

[michaeljcavanaugh]

@diablorave1 You are saying that your wired device slows down when the wireless computer downloads a large file? I assume that the router is both the wired and wireless provider and the file is coming to the WAN port of your router. If this is accurate, port priority would not help you because all traffic is coming in one interface. You need to traffic shape and prioritize the traffic being handed to your router at the next hop router as you have little control over what is being handed to you.

[delabuen]

Hi Mike. Just a quick question. If the router does not offer QoS service but has traffic shaping set up, do you think by setting up the QoS on the switch, it would make my voice packets move more freely? Thanks

[michaeljcavanaugh]

@delabuen If you set up QoS on the switch, voice will take priority on the switch, but will run into issues on the router if the router is congested. QoS is a hop by hop configuration, meaning every device must participate for end to end QoS to occur.

[thelostpackets]

Great explanation but I have several questions. Right now our pseudo voip is an archaic NEC Aspire system and our office router is a Cisco 2801. So data traffic is 192.168.1.0/24 and voice traffic is 192.168.2.0. I have a bonded 3MB pipe that connects two offices, say Atlanta and Miami, using ppp Multilink. Can I setup QoS on the 2801 based on subnet instead of packet type? So priotize 192.168.2.0/24 first? Thanks for any input.

[michaeljcavanaugh]

@thelostpackets Yes, you can match traffic based on subnet vs DSCP mark and place that traffic in the priority queue.

[Rhypes99]

very understandable tutorial. best overhead explanation I have seen.

[Inzolity]

Thank you. It's so great to get this stuff "refreshed" if you will ;)

[Alidashti2010]

Thank you

[GreedeeVids]

Thanks for taking the time to explain this to me my friend. Mike your a great teacher. You explained this very well and I got it first try :)

[tias88]

Big thanks to you for this video, i am a beginner in Networking, haven't done that much more then installing some simple auto-configurating devices, i have although just recieved my first Fiber Switch (48 ports) and a 1U router aswell, and i desperately need to set up QoS on this rig, so thanks for explaining it in a straight and easy way

[INquantico]

excellent explanation. I read a 40 slides presentation and got allot less then this. Thank you.

[RaulCasillas08]

Hey Mike , May i ask you what is the difference between COS & QOS ? Is COS part of QOS but for Layer 2 i.e. is COS = QOS for L2 ( on switches ) ?

Thanks prof.

[RaulCasillas08]

QOS are three things if am not wrong

Classifiying , Marking & Policing

[TheYouSphere]

You're great at explaining things, just one suggestion. Take a few introductory to cartooning courses, your diagrams will definintely become nicer as a result, and you'll have fun along the way.

[windsorize]

nice explanation. thanks for that.