RE: Trust VoIP and remark Data

From: Scott Morris (smorris@ipexpert.com)
Date: Fri Dec 14 2007 - 19:09:30 ART


You'll also find other things moving forward like LLDP (802.1ab) which is a
more industry-standard version of CDP.

Scott Morris, CCIE4 (R&S/ISP-Dial/Security/Service Provider) #4713, JNCIE-M
#153, JNCIS-ER, CISSP, et al.
CCSI/JNCI-M/JNCI-ER
VP - Technical Training - IPexpert, Inc.
IPexpert Sr. Technical Instructor

A Cisco Learning Partner - We Accept Learning Credits!

smorris@ipexpert.com

 

Telephone: +1.810.326.1444
Fax: +1.810.454.0130
http://www.ipexpert.com

 

 

-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of Phil
Priest
Sent: Friday, December 14, 2007 5:52 AM
To: Darren Johnson; nhatphuc; Cisco certification
Subject: RE: Trust VoIP and remark Data

Hi All,

A side issue but on the same subject...

Does anybody have a document that details the exact process with regards to
the voice vlan and using CDP. I know that Mitel phones use CDP and negotiate
themselves into the voice vlan if the voice vlan command exists but I just
want more details on the exact process.

Regards

Phil

-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
Darren Johnson
Sent: 13 December 2007 11:46
To: 'nhatphuc'; 'Cisco certification'
Subject: RE: Trust VoIP and remark Data

Hey there! I believe your second option is wrong, you don't need the
override and you need to trust cos. I would do it like this....

mls qos trust device cisco-phone
mls qos trust cos
mls qos cos 1

This says trust the COS value ONLY if a Cisco phone is detected via CDP, and
any packets/frames without a COS value (such as those received from a PC on
the native vlan) use a COS value of 1. The COS override would 'override'
any
COS values to 1, including COS values received from the phone!! I don't
believe you want to do this!

Dazzler

-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
nhatphuc
Sent: 12 December 2007 17:55
To: Cisco certification
Subject: Trust VoIP and remark Data

Hi Group,

With question: Ensure that VoIP traffic originating from the IP phones
maintains its CoS value, while traffic originating from the PCs is remarked
with a CoS of 1

I see 2 ways to answer. The first seems to be better, but I don't see
anything wrong with the second. Which one do you choose? Please explain.

mls qos trust cos
switchport priority extend cos 1

and
mls qos trust device cisco-phone
mls qos cos 1 override

Thank you

Phuc



This archive was generated by hypermail 2.1.4 : Tue Jan 01 2008 - 12:04:30 ARST