QoS, HP, Cisco

[mjensen323]

Hello,

My network consists of a majority of HP switches. Over the course of the next 18 months, we will be rolling out Cisco phones and possibly adding some Cisco switches along the way.

Is it safe to say that if the Cisco 3560 or some other L3 cisco device is at the top of each stack, with some L2 HP / Cisco switches below, that QoS should be good since the phones would be attached to the 3560?

Also, is it "recommended" to put 2900 series switches in for the client access layer?

Meaning each closet would have a layer 3 at the top, followed by layer 2's?

[andtoth]

Hi,

The devices which are recommended depend on your needs and the type and amount of traffic which they will need to handle. Usually it's a best practice to use L2 as access layer and L3 in the distribution layer. Based on your needs, you might want to use L3 in the access layer as well.

The IP Phones by default tag voice traffic with a CoS value so that it gets higher priority in the network and this value can be retained throughout the network if devices are configured properly.

I would recommend you to review the following documentations about Design recommendations and best practices.

Internetwork Design Guide

http://www.cisco.com/en/US/docs/internetworking/design/guide/idg4.html

Cisco SAFE Reference Guide

http://www.cisco.com/en/US/docs/solutions/Enterprise/Security/SAFE_RG/SAFE_rg.html

Medianet Campus QoS Design 4.0

http://www.cisco.com/en/US/docs/solutions/Enterprise/WAN_and_MAN/QoS_SRND_40/QoSCampus_40.pdf

Enterprise QoS Solution Reference Network Design Guide

http://www.cisco.com/en/US/docs/solutions/Enterprise/WAN_and_MAN/QoS_SRND/QoS-SRND-Book.html

Best regards,

Andras

[mjensen323]

When is it appropriate to run Layer 2 or Layer 3 at the access layer?

Each location would have no more than 20 phones all plugged into a single switch in the closet, however, there are about 100 ports (Non-VOIP) that would be connected below it to computer labs, etc..

[andtoth]

Layer 3 usually makes sense if you have different customers on each port and would like to separate them.

In your case, Layer 2 seems to be a good choice for the access layer.

[mjensen323]

I am in a K-12 school district.

[andtoth]

You might want to check the following documentation as well.

Cisco Service Ready Architecture for Schools Design Guide

http://www.cisco.com/en/US/docs/solutions/Enterprise/Education/SchoolsSRA_DG/SchoolsSRA-DG.html

Andras