Ethernet Switches & Routers

Reply
Occasional Contributor
Posts: 8
Registered: ‎07-30-2010

QOS questions

Any help is appreciated.

We are using Cisco phones with foundry layer 2 & 3 switches.

My questions are, do the foundry devices change the cos/dscp marking that the phones mark the traffic with in any way? by default.

Does anyone have this same setup and if so, what kind of QOS COS to DSCP conversions are you doing?  Is there a template for this?  I would think other companies must have tackled this before.

Should I just map the voice vlan to the priority queue?

Thank you,

David Tamburin

Super Contributor
Posts: 1,087
Registered: ‎12-13-2009

Re: QOS questions

Hi dtamburin,

     What platform/switches are you using.  Fastiron, Bigiron or Netiron?

Thanks

Michael.

Super Contributor
Posts: 1,087
Registered: ‎12-13-2009

Re: QOS questions

Here is the default DSCP to priority mappings for FastIron's

TABLE 140

Default DSCP to internal forwarding priority mappings

Internal forwarding priority DSCP value

0 (lowest priority queue) 0 – 7

1      8 – 15

2      16 – 23

3      24 – 31

4      32 – 39

5      40 – 47

6      48 – 55

7      (highest priority queue) 56 – 63

Thanks

Michael.

Occasional Contributor
Posts: 8
Registered: ‎07-30-2010

Re: QOS questions

Thanks for your help Michael,

This particular questions would be for our big irons.

Thanks,

Davidt  

Super Contributor
Posts: 1,087
Registered: ‎12-13-2009

Re: QOS questions

Enabling Marking

This command enables marking of the 802.1p field and/or the DSCP field in the ToS byte of an IP header.

Syntax:

qos-tos mark cos | dscp

The cos | dscp parameter specifies the type of marking.

cos – The device changes the outbound packet’s 802.1p priority value to match the results of the device’s

QoS mapping from the specified trust level.

dscp – The device changes the outbound packet’s DSCP value to match the results of the device’s QoS

mapping from the specified trust

Configuring the QoS Mappings

The Foundry device maps a packet’s 802.1p or DSCP value to an internal forwarding priority. The default

mappings are listed in Table 18.1 through Table 18.4. You can change the following mappings as described in this

section:

• CoS –> DSCP

• DSCP –> DSCP

• DSCP –> internal forwarding priority

• CoS –> internal forwarding priority

The mappings are globally configurable and apply to all interfaces.

NOTE:

In a configuration where you have marking enabled with the trust level set to CoS, you must enter the ip

rebind-acl all

command at the global CONFIG level of the CLI after making the mapping change. This applies to

mappings that are configured using the qos-tos map command.

NOTE:

The mappings are globally configurable and apply to all interfaces.

Super Contributor
Posts: 1,087
Registered: ‎12-13-2009

Re: QOS questions

Hi,

See Chapter 18 - Configuring Quality of Service

of the

BigIron RX Series Configuration Guide

That is if you need to change from the defaults.  However I find that I do not have to change these as the defaults work well for me.

Thanks

Michael.

Super Contributor
Posts: 1,087
Registered: ‎12-13-2009

Re: QOS questions

Hi,

     Is this enough information to help you here? If not please let us know.

Thanks

Michael.

Join the Community

Get quick and easy access to valuable resource designed to help you manage your Brocade Network.

vADC is now Pulse Secure
Download FREE NVMe eBook