Cannot see VoIP packets under SERVICE-POLICY OUTPUT

[caislain11]

Hi Guys,
I cannot get Voip packets to use the policy map. The config is as follows:

ip cef
!
class-map match-all platinum
match access-group 102
class-map match-all plain
match access-group 101
!
!
policy-map VOIP
class platinum
priority 300
class plain
bandwidth remaining percent 100
class class-default
fair-queue
!
interface fastethernet 0/1
description *** 1m WAN LINK ***
ip address x.x.x.x x.x.x.x
service-policy output VOIP
!
access-list 101 permit ip any any
access-list 102 permit ip any any dscp ef
access-list 102 permit ip any any dscp af41
access-list 102 permit ip any any dscp 6
!


If I do a 'SHOW POLICY-MAP', I dont see any packets hitting Class-map: platinum or Class-map: plain ???

Do I need a bandwith statement under FastEternet?

Thanks in advance,

Cais

 

[KiscoKid]

You do need to set the appropriate WAN bandwidth (esp if it is Ethernet) otherwise the policy will assume it has 100mb available.

With Ethernet interfaces, you can set the bandwidth using the bandwidth statement under the interface.

You can verify the interface bandwidth available to the service policy with the 'sh pol int' command

As an aside, I can't really explain why you are getting no matches against either class esp. as the plain class captures all IP. Maybe turn on ip accounting on the fa0/1 interface and see what kind of traffic is going via that interface. Also check your routing to make sure you're actually sending output traffic via this interface!!

 

[caislain11]

Hi KiscoKid,
Thanks for that. I have discovered that both routers are on different IOS releases and will be upgrading.

I will also apply the 'BANDWIDTH 1000' statement under the Ethernet port.
I will let you know the outcome.

Thanks,
Cais

 

[ADB100]

You should see hits against the policy map if its a 'proper' router and not a switch (such as a catalyst 3550). Are you sure your traffic is beeing tagged with the appropriate DSCP values? Have you verified it with a sniffer?

HTH

Andy

 

[Fatty99]

Try using "show policy-map interface fastethernet 0/1"

If this still doesnt show matches on platinum traffic.
See if u have matches on your ACL 102 by using "show ip access-list"
If u dont have any matches their, then you traffic indeed is not tagged with correct DSCP values. U could check this by building an test ACL on the incoming interface.

If u do see matches in your ACL 102, but not in "show policy-map interface fa0/1" then try to use

class-map match-any platinum instead of match-all

!
class-map match-any platinum
match access-group 102
!

grtz.

 

[Rod25]

Hi Guys,
I have added the bandwidth statement but still not working. I am not even seeing packets under 'class-map match-all plain'... I guess I need to see packets hear first. I might use the command recommended above:


class-map match-any platinum
match access-group 102
class-map match-all plain
match access-group 101


Thanks,
Rod

 

[Jsteve]

I have been woking with cisco TAC on this very issue. I believe it may be an undiscoverd bug. You can see the markings by entering the following


(enter this command under all interfaces, also adjust to what ever your markings are)

Int range f0/1 - 24
mls qos monitor dscp 6 16 24 32 41 46

then enter
show mls qos interface f0/1 statistics

Please nute that this is provided that your uplinks are trusted, which I don't see in your config above.

 

[plshlpme]

this is how we do our policies
i had tried what you are doing before and using the access-lists never seemed to work.

class-map match-any Platinum
match ip precedence 5 6
class-map match-any Plain
match ip precedence 0 1 2 3 4 7
!
!
policy-map VOIP
class Platinum
priority 300
class Plain
bandwidth remaining percent 100
class class-default
fair-queue

 

[caislain11]

Hi Guys,

It ended up that DSCP settings were not added to PBX. The network is a follows:

Digital extensions that can communicate via VOIP over the WAN. I configured the Cisco routers at both ends with QOS. Spoke to PBX provider and they enable DSCP settings. Now I am getting hits.

2 Questions:

Should QOS be configured on LAN Switch for IP pbx ?

I am not seeing hits under 'access-list 102 permit ip any any dscp 6' ?? I thought this was for call signalling?


Extended IP access list 102
10 permit ip any any dscp ef (69328 matches)
20 permit ip any any dscp af41
30 permit ip any any dscp 6

Thanks again for you input,
Cais

 

[ADB100]

The default DSCP values depend on the manufacturer. I know Cisco use DSCP EF (46) for Media, DSCP CS3 (24) & DSCP AF31 (26) for call signalling. Ericsson don't seem to have a 'default' and you configure what you want, Nortel set DSCP 44 for everthing by default, but tag at Layer-2 with CoS 6......

I have found that writing access-layer classification and policers is the best way but you need a list of ports the IP Phones/PBX's use to create these class-maps and policies.

HTH

Andy