QoS Doubt

Arjun Dabol · ‎03-15-2017

Hi Experts

recently one of customer shared their QoS Plan for upcoming network and mentioned that they are going with 8 tier QoS model..something like below example :

Tier	app name	class	DSCP	COS	bw
8	Voip	EF	46	5	20
7	video type 1	CS4,AF41	32,34	4,4	23
6	streaming video	CS5,AF31	40,26	5,3	10

.

My Doubt is If I want to convert this table in to a config on cisco device what it will be called - Shaping ? or Policing ?

And how will i create actual configuration - will it be using class-map--policy-map...service map applied on interface...etc... ?

thanks

Joseph W. Doherty · ‎03-15-2017

Converting such a table depends much on the platform.

Whether you need/use shaping or policing depends on information not in your table. For example, VoIP is often given LLQ or PQ treatment, but your table only notes bw=20, which doesn't tell us if LLQ or PQ should be used and/or whether BW is a minimum, maximum or both.

Devices that support MQC and CBWFQ would probably have class and policy maps, but not all Cisco devices support those, and on swtiches, both are often feature limited due to hardware capabilities.

Arjun Dabol · ‎03-17-2017

Thanks for your reply.

I was thinking that In that case what EF indictes ? does it not indicate that Voip should be treated with utmost priority ..and can we not think it as priority queue ?

Joseph W. Doherty · ‎03-17-2017

What does EF indicate? It stands for expedited forwarding.

The RFC that defines it, doesn't explicitly tie it to VoIP or require it to have the utmost priority. PQ might be used to support it, but that's not guaranteed.