From: Scott Morris (swm@emanon.com)
Date: Wed Mar 31 2004 - 11:10:32 GMT-3
There is no "better" when it comes to using bandwidth or
bandwidth-percent... It's all going to be relative to your specific needs
and configuration (or your specific lab scenario). If you have the option
to do whatever you want (real-life), do whichever you are more comfortable
with.
A reason that some people use the percetage option is because it's not tied
to any particular links' bandwidth, which means you can create policies that
are static throughout your organization and you don't necessarily have to
worry about what the link speed is. But that's just one reason.
As for how much bandwidth to allocate, you'll need to work the math. How
many simultaneous phone calls do you want? What codec are you using? What
other applications (critical or otherwise) will the voice traffic be
competing with? Lotsa questions to think about, but there is not one
particular "right" answer. (In the lab or in the real world)
Your mileage may vary.
HTH,
Scott Morris, CCIE4 (R&S/ISP-Dial/Security/Service Provider) #4713, CISSP,
JNCIS, et al.
IPExpert CCIE Program Manager
IPExpert Sr. Technical Instructor
swm@emanon.com/smorris@ipexpert.net
http://www.ipexpert.net
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of Mark
Rushby
Sent: Wednesday, March 31, 2004 3:03 AM
To: ccielab@groupstudy.com
Subject: VOIP/QOS
Hi Group
I have checked the archives and found some useful info which I have used to
come to the following solution. I have lab'd my solutions up and tested it
as much as possible with the kit I have.
I have the following situation.
site A leased 2048kbps siteB
2610 ----------------------------------------------------2600
| |
| |
3com 4400 3com 4400
The company are going to introduce VOIP between the 2 sites. The 3com
switches will be vlan with a voice and data vlans. I am going to implement
QOS over the leased line for the voice traffic. I have lab'd the following
solution up and it seems to work ok. Bearing in mind I have no VOIP
capabilities (advertising capabilities with my neighbour
:-) ) it is hard to fully test. I have generated traffic on the port
range 16384 20000 and all seems to be ok.
This my intended solutions:
Router(config)# access-list 102 permit udp host 10.10.10.10 host 10.10.10.20
range 16384 20000
Router(config)# class-map voice
Router(config-cmap)# match access-group 102
Router(config)# policy-map policy1
Router(config-pmap)# class voice
Router(config-pmap-c)# priority 50
Router(config-pmap)# class class-default Router(config-pmap-c)# fair-queue
So is it better to use a set bandwidth or a percentage? And is there a
calculation to calculate the required bandwidth for x amount of users?
The second issue i have is the current ios version on the 2600's is
12.0(2) and the priority command was only introduced in 12.0(5). So i will
have to upgrade their ios to a new version. The routers both have 32mb Ram
and 8 flash. What would be the best image to use and will i need to upgrade
the memory ( expect i will just want some conformation).
Is there a tool on Cisco site to find out what memory is required for each
ios version?
I am still waiting for more info from the customer on the amount of voip
users and the ip address range for the voip vlan etc.
TIA
Mark Rushby
This archive was generated by hypermail 2.1.4 : Thu Apr 01 2004 - 08:15:50 GMT-3