[c-nsp] VoIP QoS on Cisco 2950 series switches

Matthew Crocker mcrocker at crocker.com
Wed Jul 25 14:29:00 EDT 2007


Hello,

  I have a Cisco 2950-LRE switch and I'm trying to enable QoS for  
some VoIP traffic flowing across the switch.  All interesting traffic  
has DSCP set to EF.  I followed some online docs (auto qos voip  
trust) on the interfaces but it doesn't seem to be doing the trick

any ideas?

sh version
Cisco Internetwork Operating System Software
IOS (tm) C2950lre Software (C2950lre-I6L2Q4-M), Version 12.1(22)EA4a,  
RELEASE SOFTWARE (fc1)
Copyright (c) 1986-2005 by cisco Systems, Inc.
Compiled Fri 16-Sep-05 11:24 by yenanh
Image text-base: 0x80010000, data-base: 0x805B2000

ROM: Bootstrap program is C2950lre boot loader

Crocker_LRE_Spfld uptime is 22 hours, 39 minutes
System returned to ROM by power-on
System image file is "flash:/c2950lre-i6l2q4-mz.121-22.EA4a/c2950lre- 
i6l2q4-mz.121-22.EA4a.bin"

cisco WS-C2950ST-8-LRE (RC32300) processor (revision G0) with 47478K  
bytes of memory.
Processor board ID FHK0949R04C
Last reset from system-reset
Running Enhanced Image
2 Gigabit Ethernet/IEEE 802.3 interface(s)
8 Long Reach Ethernet interface(s)
The password-recovery mechanism is enabled.

32K bytes of flash-simulated non-volatile configuration memory.
Base ethernet MAC Address: 00:15:63:79:5F:00
Motherboard assembly number: 73-8380-11
Power supply part number: 341-0039-01
Motherboard serial number: FOC09483QMF
Power supply serial number: PHI0945K05R
Model revision number: G0
Motherboard revision number: B0
Model number: WS-C2950ST-8-LRE
System serial number: FHK0949R04C
SFP Module Board Assembly Part Number: 73-7757-03
SFP Module Board Revision Number: A0
SFP Module Board Serial Number: CAT094513KH
CLEI Code Number: CNS6NSMAAC
Configuration register is 0xF


Config:

!
wrr-queue bandwidth 10 20 70 1
wrr-queue cos-map 1 0 1
wrr-queue cos-map 2 2 4
wrr-queue cos-map 3 3 6 7
wrr-queue cos-map 4 5
no errdisable detect cause gbic-invalid
mls qos map cos-dscp 0 8 16 26 32 46 48 56
ip subnet-zero
!
interface GigabitEthernet0/1
switchport mode trunk
media-type sfp
flowcontrol send off
mls qos trust dscp
auto qos voip trust
!
interface GigabitEthernet0/2
flowcontrol send off
!
interface LongReachEthernet0/1
description FutureWorks
switchport access vlan 207
switchport mode access
bandwidth 2000
cpe type CISCO575-LRE
profile LRE-2
flowcontrol send off
mls qos trust dscp
auto qos voip trust
random-detect
!
Crocker_LRE_Spfld#show queueing interface l0/1
Interface LongReachEthernet0/1 queueing strategy: random early  
detection (WRED)
     Exp-weight-constant: 9 (1/512)
     Mean queue depth: 0

     Class   Random       Tail    Minimum    Maximum     Mark
               drop       drop  threshold  threshold  probability
       0          0          0         20         40     1/10
       1          0          0         22         40     1/10
       2          0          0         24         40     1/10
       3          0          0         26         40     1/10
       4          0          0         28         40     1/10
       5          0          0         31         40     1/10
       6          0          0         33         40     1/10
       7          0          0         35         40     1/10
      rsvp        0          0         37         40     1/10

Crocker_LRE_Spfld#show mls qos interface l0/1
LongReachEthernet0/1
trust state: trust dscp
trust mode: trust dscp
COS override: dis
default COS: 0
pass-through: none
trust device: none



More information about the cisco-nsp mailing list