From: Scott Morris (smorris@ipexpert.com)
Date: Fri Oct 26 2007 - 17:06:38 ART
That would be "CCIE in a GIGANTIC Nutshell". :)
-----Original Message-----
From: Gregory Gombas [mailto:ggombas@gmail.com]
Sent: Friday, October 26, 2007 3:18 PM
To: Tarun Pahuja
Cc: Scott Morris; Cisco certification
Subject: Re: IP Telephony Topics for R+S
Yes Scott, that was quite a succinct yet crystal clear explanation - thanks!
Can we expect a "CCIE in a Nutshell" in book stores soon?
Tarun, thanks for sharing - I'm curious how did using trunk ports impact
CPU?
Thanks,
Greg
On 10/26/07, Tarun Pahuja <pahujat@gmail.com> wrote:
> Gregory,
> Scott did a tremendously job in explaining the concept.
> On Many switches even thought the port is configured as a trunk, the
> phone would still come up and register with the Call Manager.
>
> One of my customers called me one day and told me that his 6500 switch
> had 72% process utilization which was impacting performance.On
> Investigating the matter I found out that he had mis configured all 48
> ports on a line card as trunks ports for IP Phone connectivity.
> Removing the trunking on those ports and making them part of voice and
> access vlan brought the CPU utilization back to 19%.
>
> Some old network module switches still require administrator to
> configure them as trunk ports with native vlan for IP Phone
> connectivity.
>
> HTH,
> Tarun
>
> On 10/26/07, Scott Morris <smorris@ipexpert.com> wrote:
> > IP Telephony itself isn't part of the lab, but familiarity with some
> > of the topics is a "good thing to know". :)
> >
> > In a nutshell, your voice vlan is sent with an 802.1Q tag and your
> > PC/Data traffic is sent untagged. In a "pure trunk" concept this
> > means your PC data would be your native vlan and you'd have a trunk
running.
> >
> > For security purposes, people used to get all up in arms about
> > needing to use "switchport trunk allowed" and restrict what things
> > could or could not be sent over that trunk for the great fear of
> > hackers. Cisco has made it simpler with most switches where you can
> > now simply be in 'switchport mode access'.
> >
> > This, when we look at it, doesn't allow trunking. The 'switchport
> > voice vlan' command, however, provides a specific override allowing
> > tagging of one single vlan only. So we've made things better for
> > the security conscious as well as simpler for the configuration.
> >
> > HTH,
> >
> >
> > 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 Gregory Gombas
> > Sent: Friday, October 26, 2007 11:27 AM
> > To: Cisco certification
> > Subject: IP Telephony Topics for R+S
> >
> > Not sure if IP telephony is in scope for the R+S but seems to crop
> > up in the IE workbooks a lot. I was hoping someone could help clear up
some confusion:
> >
> > 1. When connecting an cisco IP phone to a 3550/3560, does it
> > automatically create an 802.1q trunk?
> >
> > 2. According to the DOC cd:
> > "You can configure an access port with an attached Cisco IP Phone to
> > use one VLAN for voice traffic and another VLAN for data traffic
> > from a device attached to the phone. "
> >
> > How is it possible two have two different VLANS run over a switch
> > port configured in access mode?
> >
> > 3. Can someone recommend some good (but short) reads for connecting
> > IP telephones to Cisco switches? I already have this one:
> >
> > http://www.cisco.com/univercd/cc/td/doc/product/lan/cat3560/12240se/
> > scg/swvo
> > ip.htm
> >
> > Thanks,
> > Greg
> >
> > ____________________________________________________________________
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> >
> > ____________________________________________________________________
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