02-09-2012 02:43 PM - edited 03-07-2019 04:50 AM
Hi,
The company I work have finally decided to enter the 21st century and invest in a new telephone system (Interactive Intelligence) to replace the legacy system which has served us well for the past 10 years. The project has only just started and involves upgrading sections of CAT3 cabling to CAT6, replacing Cisco 3550 switches in one area of the building with Cisco 4507 switches and upgrading our Core switches with Cisco Nexus 7010's.
The area that concerns me most is enabling the network for qos as I have very little experience with it. At the moment Im trying to read as much documentation as I can on QOS to bring myself up to speed.
The access layer switches will consist of a mixture of Cisco 3750 & 4507 switches connected to Cisco Nexus 7010 switches which will form a collapsed aggregation & core layer.
Basically I'm after any advice on how I should approach this daunting task of making sure the network will support VOIP.
Any advice is very much appreciated.
Many Thanks
Darren
02-09-2012 04:36 PM
Hi,
QOS is a big subject nowadays.
This SRND doc seems to be popular
http://www.cisco.com/en/US/docs/solutions/Enterprise/WAN_and_MAN/QoS_SRND_40/QoSCampus_40.html
HTH
Alex
02-09-2012 06:59 PM
Do you want to know about QoS or VoIP?
02-09-2012 11:23 PM
You need to start with SRND link to which posted by Alex, understand needs of voice and any other priority traffic in the network and then read QoS guide for used platforms:
Here is Nexus 7000 QoS description and config guide:
http://www.cloudcentrics.com/?p=784
HTH,
Alex
02-10-2012 01:21 AM
Hi,
Think I need to understand both Qos and voip but primarily qos. We do have a subsiduary company which already uses VOIP. I've looked at some of the config so just trying to get my head around it.
interface GigabitEthernet1/10
service-policy input Input-Dscp-Policy
service-policy output Output-Policy
class-map match-all Nortel-Voice-QosGroupEF
match qos-group 46
class-map match-all Nortel-Control-Dscp
match dscp cs5
class-map match-all Nortel-Voice-Dscp
match dscp ef match
policy-map Input-Dscp-Policy
class Nortel-Voice-Dscp
set qos-group 46
set cos 5
class Nortel-Control-Dscp
set qos-group 24
policy-map Output-Policy
class Nortel-Voice-QosGroupEF
priority
police cir percent 33
class Nortel-Control-QosGroup24
bandwidth remaining percent 5
class class-default
dbl
If my understanding is correct on the input side the RTP traffic is marked by the phone with a dscp value of ef, the policy map then sets the dscp value to 46 and the cos value to 5. The signaling traffic is marked with dscp value of 24. On the output side the policy map matches traffic with dscp value of 46 and places this traffic in the priority queue which is guranteed 33% of the bandwidth. If the RTP traffic exceeds 33% then it is dropped. The signaling traffic is allocated 5% of the remaining traffic using CBWF. All other traffic uses the default class.
02-10-2012 03:02 AM
Hi,
It is always a good idea to ask the Nortel/Avaya engineers to set the DSCP for signalling to 24 when their kit is connecting to a CISCO LAN/WAN set up.
Thankfully Nortel/Avaya use dscp 46(EF) for the VOICE traffic.
You can usually use a config like this on a 3750/3560
!
interface FastEthernet1/0/25
description *** Nortel IP Phone & PC Port ***
switchport access vlan 5
switchport mode access
switchport voice vlan 705
srr-queue bandwidth share 1 70 25 5
priority-queue out
mls qos trust dscp
spanning-tree portfast
!
This moves the trust boundary to phone trusdting its DSCP values
HTH
Alex
02-10-2012 07:43 AM
Just asking..if our local network using fast ethernet or gigabit to the desktop, do we need to setup QoS for the voice?
IP phone marking the packets with dscp EF. Is it different with different brand and model for IP phone? How to check the dscp EF for IP Phone? I'm using Aastra IP Phone.
Please advice . thanks
Discover and save your favorite ideas. Come back to expert answers, step-by-step guides, recent topics, and more.
New here? Get started with these tips. How to use Community New member guide