Solved: Re: QoS policy for Nortel phones

jeff_turl · ‎03-12-2012

We use Nortel IP phones (1140E), according to the Nortel documentation Voice media is tagged by the phones as DSCP 46 and Signalling as DSCP 40.

Can someone tell me where i have gone wrong! On my switch (3750) i trust the DSCP and have the cos-dscp map set

The router (2621XM) i have the COS-DSCP set, and a service policy. However when i view the service policy (atm0/0.1) i don't see anything tagged as DSCP 46 only 48:

Switch:

mls qos map cos-dscp 0 8 16 24 32 40 46 56

mls qos

interface r FastEthernet1/0/1 - 48

switchport access vlan 100

switchport mode access

switchport voice vlan 300

priority-queue out

mls qos trust dscp

spanning-tree portfast

Router:

mls qos map cos-dscp 0 8 16 24 32 40 46 56

class-map match-any Voice-Media

match ip dscp ef

match ip dscp cs6

class-map match-any Voice-Signalling

match ip dscp cs5

policy-map Torbay_VOIP

class Voice-Media

priority percent 20

class Voice-Signalling

bandwidth percent 5

class class-default

fair-queue

random-detect

interface ATM0/0

no ip address

no atm ilmi-keepalive

!

interface ATM0/0.1 point-to-point

description BT Baseband PREM to Pgn Library

ip address 172.25.200.234 255.255.255.252

cdp enable

pvc 0/32

vbr-nrt 4378 4378 1

encapsulation aal5snap

service-policy output Torbay_VOIP

#sh policy-map interface atm 0/0.1

ATM0/0.1: VC 0/32 -

Service-policy output: Torbay_VOIP

Class-map: Voice-Media (match-any)

80 packets, 14229 bytes

5 minute offered rate 0 bps, drop rate 0 bps

Match: ip dscp ef (46)

0 packets, 0 bytes

5 minute rate 0 bps

Match: ip dscp cs6 (48)

80 packets, 14229 bytes

5 minute rate 0 bps

Queueing

Strict Priority

Output Queue: Conversation 136

Bandwidth 20 (%)

Bandwidth 875 (kbps) Burst 21875 (Bytes)

(pkts matched/bytes matched) 80/14229

(total drops/bytes drops) 0/0

Class-map: Voice-Signalling (match-any)

9 packets, 450 bytes

5 minute offered rate 0 bps, drop rate 0 bps

Match: ip dscp cs5 (40)

9 packets, 450 bytes

5 minute rate 0 bps

Queueing

Output Queue: Conversation 137

Bandwidth 5 (%)

Bandwidth 218 (kbps)Max Threshold 64 (packets)

(pkts matched/bytes matched) 1/50

(depth/total drops/no-buffer drops) 0/0/0

Class-map: class-default (match-any)

5735 packets, 3604650 bytes

5 minute offered rate 234000 bps, drop rate 0 bps

Match: any

Queueing

Flow Based Fair Queueing

Maximum Number of Hashed Queues 128

(total queued/total drops/no-buffer drops) 0/0/0

exponential weight: 9

acampbell · ‎03-15-2012

Jeff,

I take it that you only have the ONE sub interface.

Then the band statement should be applied to both

int atm 0/0

band 4096

int atm 0/0.1

band 4096

The other thing I wanted to mention was the amount of EF9 (SPEECH) bandwidth is codec related

Approx 80K per G711 call

Approx 25K per G729 call

Make sure your % priority statement give you enough for the number of simultaneous calls you want

E.G.

20 calls using G729 = app 500K

If you reserve only 20% of a 1M link then you would over subscribe and probably have poor quality complaints when too many calls are made

IE you would need 50% reservation

HTH

Alex

please rate useful posts

Regards, Alex. Please rate useful posts.

View solution in original post

acampbell · ‎03-13-2012

Jeff,

Can you post the config of the 3750 port which connects the router.

Also is this a BCM or Meridian CS1000

Regards

Alex

Regards, Alex. Please rate useful posts.

jeff_turl · ‎03-14-2012

the Phone system is a CS1000.

Here is the config from the switch:

service timestamps debug uptime

service timestamps log uptime

service password-encryption

!

hostname Bishops-Place-Switch1

!

boot-start-marker

boot-end-marker

!

enable secret 5 xxxx

!

username ciscoadmin password 7 xxxx

!

aaa new-model

!

aaa authentication login default group radius local

aaa authentication login console none

aaa authentication enable default group radius enable

!

aaa session-id common

clock timezone GMT 0

clock summer-time GMT recurring last Sun Mar 1:00 last Sun Oct 2:00

switch 1 provision ws-c3750-24p

system mtu routing 1500

ip routing

ip domain-name torbay.local

ip name-server 172.22.200.22

ip name-server 172.22.200.6

!

mls qos map cos-dscp 0 8 16 24 32 40 46 56

mls qos

!

crypto pki trustpoint TP-self-signed-1164516992

enrollment selfsigned

subject-name cn=IOS-Self-Signed-Certificate-1164516992

revocation-check none

rsakeypair TP-self-signed-1164516992

!

power inline consumption default 10500

!

spanning-tree mode rapid-pvst

spanning-tree extend system-id

!

vlan internal allocation policy ascending

lldp run

!

interface range FastEthernet1/0/1 - 24

switchport access vlan 100

switchport mode access

switchport voice vlan 300

priority-queue out

mls qos trust dscp

spanning-tree portfast

!

interface GigabitEthernet1/0/1

description Trunk to Router

switchport trunk encapsulation isl

switchport mode trunk

speed 100

duplex full

priority-queue out

mls qos trust dscp

!

interface GigabitEthernet1/0/2

shutdown

!

interface Vlan1

no ip address

shutdown

!

interface Vlan100

ip address 172.23.146.1 255.255.255.0

!

interface Vlan300

ip address 172.18.146.1 255.255.255.0

!

ip classless

ip route 172.22.0.0 255.255.0.0 172.23.146.254

ip route 172.25.0.0 255.255.0.0 172.18.146.254

ip route 0.0.0.0 0.0.0.0 172.23.146.254

ip http server

ip http access-class 11

ip http secure-server

!

ip sla enable reaction-alerts

logging 172.22.200.254

access-list 11 remark Restrict HTTP access to Networks

access-list 11 permit 172.22.200.254 log

access-list 11 permit 172.22.100.0 0.0.0.31 log

access-list 11 permit 172.23.146.0 0.0.0.3 log

access-list 11 deny any log

access-list 11 remark Restrict HTTP access to Networks

snmp-server community plentyaft3r RO 11

snmp-server enable traps snmp authentication

snmp-server enable traps config

radius-server host 172.22.200.87 auth-port 1645 acct-port 1646 key 7 xxxx

!

banner motd ^C Bishops Place Switch1 ^C

!

line con 0

line vty 0 4

access-class 11 in

exec-timeout 0 0

password 7 xxxx

line vty 5 15

access-class 11 in

exec-timeout 0 0

password 7 xxxx

!

ntp clock-period 36028832

ntp server 172.22.200.22

end

acampbell · ‎03-14-2012

Jeff,

Can you issue a couple commands on your 3750

Bishops-Place-Switch1# clear mls qos int stat

Wait about 10 mins and make your that some IPT calls have been placed over the WAN

then post the ouput of

show mls qos int g1/0/1 stat

Regards

Alex

Regards, Alex. Please rate useful posts.

jeff_turl · ‎03-15-2012

Alex, thanks for your responce.

Here is the output from one of the access ports:

FastEthernet1/0/23

trust state: trust dscp

trust mode: trust dscp

trust enabled flag: ena

COS override: dis

default COS: 0

DSCP Mutation Map: Default DSCP Mutation Map

Trust device: none

qos mode: port-based

Here is the output from the trunk port:

GigabitEthernet1/0/1

trust state: trust dscp

trust mode: trust dscp

trust enabled flag: ena

COS override: dis

default COS: 0

DSCP Mutation Map: Default DSCP Mutation Map

Trust device: none

qos mode: port-based

jeff_turl · ‎03-15-2012

show mls qos int g1/0/1 stat:

dscp: incoming

-------------------------------

0 - 4 : 280 0 0 0 0

5 - 9 : 0 0 0 0 0

10 - 14 : 0 0 0 0 0

15 - 19 : 0 0 0 0 0

20 - 24 : 0 0 0 0 0

25 - 29 : 0 0 0 0 0

30 - 34 : 0 0 0 0 0

35 - 39 : 0 0 0 0 0

40 - 44 : 0 0 0 0 0

45 - 49 : 0 0 0 0 0

50 - 54 : 0 0 0 0 0

55 - 59 : 0 0 0 0 0

60 - 64 : 0 0 0 0

dscp: outgoing

-------------------------------

0 - 4 : 24 0 0 0 0

5 - 9 : 0 0 0 0 0

10 - 14 : 0 0 0 0 0

15 - 19 : 0 0 0 0 0

20 - 24 : 0 0 0 0 0

25 - 29 : 0 0 0 0 0

30 - 34 : 0 0 0 0 0

35 - 39 : 0 0 0 0 0

40 - 44 : 141 0 0 0 0

45 - 49 : 0 0 0 96 0

50 - 54 : 0 0 0 0 0

55 - 59 : 0 0 0 0 0

60 - 64 : 0 0 0 0

cos: incoming

-------------------------------

0 - 4 : 301 0 0 0 0

5 - 7 : 0 0 0

cos: outgoing

-------------------------------

0 - 4 : 24 0 0 0 0

5 - 7 : 141 96 0

output queues enqueued:

queue: threshold1 threshold2 threshold3

-----------------------------------------------

queue 0: 141 0 0

queue 1: 40 3 1778

queue 2: 0 0 0

queue 3: 0 0 0

output queues dropped:

queue: threshold1 threshold2 threshold3

-----------------------------------------------

queue 0: 0 0 0

queue 1: 0 0 0

queue 2: 0 0 0

queue 3: 0 0 0

Policer: Inprofile: 0 OutofProfile: 0

acampbell · ‎03-15-2012

Jeff,

The issue you see is due to the cos-dscp map
The packets leave the swith towards the router as COS 6 DSCP CS6 (48)

This is usually used for network control data like HSRP etc.

Throught the WAN you really want your EF traffic to pass outbound as DSCP EF (46)

By default Nortel use DSCP CS5 (40) for signalling
We want to see this in the loose AF3 Q.

On your 3750 can you try making the follwing changes :-

!
!
mls qos map cos-dscp 0 8 16 40 32 46 48 56
!

On you router change

!

mls qos map cos-dscp 0 8 16 40 32 46 48 56

!

class-map match-any Voice-Media

match ip dscp ef

no match ip dscp cs6

!

Give this a try and retest.

Regards
Alex

Regards, Alex. Please rate useful posts.

jeff_turl · ‎03-15-2012

Alex, thanks for your help, i see traffic leaving the router atm int makred as dscp ef 46 now!!

Do i need to do anything for the signalling or does that qos map sort that out as well?

The QoS map i used previously had come from Nortel! Thanks for the useful commands i think i will have to check the rest of my other switches out now!

Bishops-Place-Router1#sh policy-map int atm 0/0.1

ATM0/0.1: VC 0/32 -

Service-policy output: Torbay_VOIP

Class-map: Voice-Media (match-any)

8133 packets, 586568 bytes

5 minute offered rate 28000 bps, drop rate 0 bps

Match: ip dscp ef (46)

8133 packets, 586568 bytes

5 minute rate 28000 bps

Queueing

Strict Priority

Output Queue: Conversation 136

Bandwidth 20 (%)

Bandwidth 875 (kbps) Burst 21875 (Bytes)

(pkts matched/bytes matched) 110/7920

(total drops/bytes drops) 0/0

Class-map: Voice-Signalling (match-any)

425 packets, 22481 bytes

5 minute offered rate 0 bps, drop rate 0 bps

Match: ip dscp cs5 (40)

425 packets, 22481 bytes

5 minute rate 0 bps

Queueing

Output Queue: Conversation 137

Bandwidth 5 (%)

Bandwidth 218 (kbps)Max Threshold 64 (packets)

(pkts matched/bytes matched) 0/0

(depth/total drops/no-buffer drops) 0/0/0

Class-map: class-default (match-any)

14184 packets, 3944802 bytes

5 minute offered rate 72000 bps, drop rate 0 bps

Match: any

Queueing

Flow Based Fair Queueing

Maximum Number of Hashed Queues 128

(total queued/total drops/no-buffer drops) 0/0/0

exponential weight: 9

class Transmitted Random drop Tail drop Minimum Maximum Mark

pkts/bytes pkts/bytes pkts/bytes thresh thresh prob

0 13738/3877650 0/0 0/0 20 40 1/10

1 0/0 0/0 0/0 22 40 1/10

2 0/0 0/0 0/0 24 40 1/10

3 0/0 0/0 0/0 26 40 1/10

4 0/0 0/0 0/0 28 40 1/10

5 0/0 0/0 0/0 30 40 1/10

6 452/67863 0/0 0/0 32 40 1/10

7 0/0 0/0 0/0 34 40 1/10

rsvp 0/0 0/0 0/0 36 40 1/10

acampbell · ‎03-15-2012

Jeff,

I think I read the same doc re the Nortel phones to cisco switches.

My opinion is that they have made a mistake in the doc.

They get you to ammenf the COS-DSP map so to me they should then have use

mls qos trust COS on the phone ports

They have used trust DSCP in the doc.

If you are using a BT WAN like IP-Clear etc you need to send your your traffic as

RTP-Media in EF

SIGNALLING in AF3

Make sure that you ask the WAN provider to put QOS throughout your WAN.If you dont your traffic will be passed through their network as BEST EFFORT even though you are trying to prioitise at your ends.

HTH

Alex

please rate useful posts.

Regards, Alex. Please rate useful posts.

jeff_turl · ‎03-15-2012

I know the document you mean, i think i will be doing some shreadding later on!!!

All our sites are back-to-back router configs, so we control the CO and CPE and just rent copper/fibre Point to Point circuits.

Please excuse my ignorance, but this is my first attempt at implementing QoS, the switches seems simple enough as these i will jsut trust the DSCP.

On the routers, do i need to do anything else for media or signalling? i assume the EF uses the priority egress queue, but i wasnt sure that my output policy was correct, as i have signalling as CS5, and i wasn't sure how much bandwidth to guarentee the phones, i have used 20% and 5% (line rate is 4608, vbr is set to 95% 4378):

class-map match-any Voice-Media

match ip dscp ef

match ip dscp cs6

class-map match-any Voice-Signalling

match ip dscp cs5

policy-map Torbay_VOIP

class Voice-Media

priority percent 20

class Voice-Signalling

bandwidth percent 5

class class-default

fair-queue

random-detect

acampbell · ‎03-15-2012

Jeff,

For the media leve out the CS6 this is network control packets

class-map match-any Voice-Media

match ip dscp ef

no match ip dscp cs6

On your router interfaces make sure you configure the correct bandwidth

int atm 0/XXXX

band 2000 (for 2M)

The QOS statements you are using are percentages % of this bandwidth

If you dont configure you will be using the Cisco defaults like 1.544M on a serial.

So that may be useless for your setup.

As for the amount of bandwidth for signalling allocating 5% sounds reasonable.

I am not sure what the actual amount is for Nortel but it is 265bps per phone or channel on cisco IPT

So 10 phones and 6 isdn channels registered over the WAN to CUCM would be 16 x 265 = 4.24Kbps

HTH

Alex

Regards, Alex. Please rate useful posts.

jeff_turl · ‎03-15-2012

Thanks Alex, sorry i had already done your recommendation of: no match ip dscp cs6

i was just looking at an old copy of the config!

the interface is a a G.SHDSL (WIC-1SHDSL v2) and is configured as follows, do i need to apply the bandwidth to the controller/ATM or ATM sub interface?

controller DSL 0/0

mode atm

line-term cpe

line-mode 4-wire enhanced

dsl-mode shdsl symmetric annex B

line-rate 4608

interface ATM0/0

no ip address

no atm ilmi-keepalive

!

interface ATM0/0.1 point-to-point

description BT Baseband PREM to Pgn Library

ip address 172.25.200.234 255.255.255.252

cdp enable

pvc 0/32

vbr-nrt 4378 4378 1

encapsulation aal5snap

service-policy output Torbay_VOIP

Thanks for the info about nortel phones 256bps is not much for signalling, is the signalling the comms from the handset back to the CS1K servers?

Regards
Jeff

acampbell · ‎03-15-2012

Jeff,

If you are using ADSL use the upstream speed IE the low one

for SDSL then use the bandwidth you have odered like 4M = 4096

Signalling should not be much but you do want it to be given some guarantee hence it is ahead of the default traffic in the policy map.

You do not want signalling packet to be delayed etc or faults like delay to dial tone or phones not answerring when the handset is lifted etc etc

Signalling is phone set to sig server for packets like off hook, dialled digits, hold pressed etc etc

HTH

Alex

Regards, Alex. Please rate useful posts.

jeff_turl · ‎03-15-2012

Alex, thanks. As i use point to point sub interfaces, does the bandwidth command go on the ATM 0/0 or ATM 0/0.1.

Each ATM interface has a just single sub interface.

Regards

Jeff

acampbell · ‎03-15-2012

Jeff,

I take it that you only have the ONE sub interface.

Then the band statement should be applied to both

int atm 0/0

band 4096

int atm 0/0.1

band 4096

The other thing I wanted to mention was the amount of EF9 (SPEECH) bandwidth is codec related

Approx 80K per G711 call

Approx 25K per G729 call

Make sure your % priority statement give you enough for the number of simultaneous calls you want

E.G.

20 calls using G729 = app 500K

If you reserve only 20% of a 1M link then you would over subscribe and probably have poor quality complaints when too many calls are made

IE you would need 50% reservation

HTH

Alex

please rate useful posts

Regards, Alex. Please rate useful posts.