OK... here's my real question:

 

If you're told to trust IP phone's Layer 2 markings, are the VG248 and
ATA considered IP phones?  If the ATA accepts the auxiliary/voice VLAN,
does that mean that it establishes and 802.1q trunk?  I don't think it
does.  There isn't a PC port, so there's no need for a trunk.  If
there's no trunk, there's no COS markings.  I know the VG doesn't.  I'm
guessing you would not consider the ATA and VG 248 "IP Phones" and need
remark at LAN ingress.

 

Here's a tip for the newbie like me:

As for layer 3, they both use PHB AF31/EF by default.  The VG has a
simple menu option for this.  The ATA uses the TOS field on the web GUI.
The DSCP field is the leftmost 6 bits.

 

For example:

 

TOS=0x000068B8 (default)

 

Control = 68 = 0110 1000, discard last two 0's, DSCP = 011010 = 26


Media = B8 = 1011 1000, discard last two 0's, DSCP = 101110 = 46

 

 

 

Greg Jost

Network Consulting Engineer

Unified Communications Practice

Cisco Systems, Inc.

214-274-1922

 

________________________________

From: Vik Malhi [mailto:[EMAIL PROTECTED] 
Sent: Thursday, April 17, 2008 4:43 PM
To: Gregory Jost (grjost); [email protected]
Subject: RE: [OSL | CCIE_Voice] 6500 marking

 

the simplified answer to this question is "yes, the ATA supports the
voice vlan."

 

Vik Malhi - CCIE #13890 
Senior Technical Instructor - IPexpert, Inc. 

Telephone: +1.810.326.1444 
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________________________________

From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Gregory
Jost (grjost)
Sent: Thursday, April 17, 2008 12:24 PM
To: Gregory Jost (grjost); [email protected]
Subject: Re: [OSL | CCIE_Voice] 6500 marking

Does CDP recognize the ATA as an IP Phone and allow you to use the
auxiliary/voice VLAN, even though there isn't PC port to extend/deny
trust to?

 

Greg Jost

Network Consulting Engineer

Unified Communications Practice

Cisco Systems, Inc.

214-274-1922

 

________________________________

From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Gregory
Jost (grjost)
Sent: Thursday, April 17, 2008 2:15 PM
To: [email protected]
Subject: [OSL | CCIE_Voice] 6500 marking

 

I don't see it mentioned anywhere that CRS, Attendant Console Queue,
MOH, Annunciator, MTP, etc. all use RTP.  If you're not allowed to trust
DSCP from CCM/CRS and Unity, then these too should be marked on the
server ports, not just signaling protocols.  

 

Thoughts?

 

 

Greg Jost

Network Consulting Engineer

Unified Communications Practice

Cisco Systems, Inc.

214-274-1922

 

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