UxBoD
@idnet.net
|  [HELP] Cisco 877 VOIP QoS & ASA5505
Hi,
I am trying to apply some QoS to inbound/outbound VOIP (IAX) traffic and need some help please  The traffic takes the following path :-
DSL -> Cisco 877 -> Cisco ASA 5505 -> Asterisk Server
I have done a little on the setup so far and have prioritised the IAX traffic on my ASA 5505 to be at the top. Now my issue is how to do the same on the 877 router. Here is my running config[code]
!
!
ip domain name XXXXXXXXXXXXXXXX.XXXXX
ip name-server XXX.XXX.XXX.XXX
ip name-server XXX.XXX.XXX.XXX
ip auth-proxy max-nodata-conns 3
ip admission max-nodata-conns 3
!
multilink bundle-name authenticated
!
shutdown vlan 2
!
username XXXXXXX privilege 15 secret 5 XXXXXXXXXXXXXXXXXXXXXXXXXX.
!
archive
log config
hidekeys
!
class-map match-any voip-class
match access-group name voip-traffic
!
policy-map voip-priority
class voip-class
priority percent 30
!
interface ATM0
no ip address
no atm ilmi-keepalive
dsl operating-mode itu-dmt
!
interface ATM0.1 point-to-point
no ip unreachables
no ip proxy-arp
pvc 0/38
encapsulation aal5mux ppp dialer
dialer pool-member 1
!
!
interface FastEthernet0
duplex full
!
interface FastEthernet1
!
interface FastEthernet2
!
interface FastEthernet3
switchport trunk native vlan 2
!
interface Vlan1
ip address XXX.XXX.XXX.XXX 255.255.255.248
ip nbar protocol-discovery
ip flow ingress
ip flow egress
!
interface Vlan2
no ip address
ip nbar protocol-discovery
!
interface Dialer0
ip unnumbered Vlan1
encapsulation ppp
dialer pool 1
dialer-group 1
ppp authentication chap callin
ppp chap hostname XXXXXXXXXXXXXXXX
ppp chap password 0 XXXXXXXXXXXXX
!
ip forward-protocol nd
ip route 0.0.0.0 0.0.0.0 Dialer0 permanent
ip route XXX.XXX.XXX.XXX 255.255.255.255 Vlan1 permanent
ip route XXX.XXX.XXX.XXX 255.255.255.255 XXX.XXX.XXX.XXX permanent
ip route XXX.XXX.XXX.XXX 255.255.255.255 Vlan1 permanent
ip route XXX.XXX.XXX.XXX 255.255.255.255 XXX.XXX.XXX.XXX permanent
ip route XXX.XXX.XXX.XXX 255.255.255.255 Vlan1 permanent
ip route XXX.XXX.XXX.XXX 255.255.255.255 XXX.XXX.XXX.XXX permanent
ip route XXX.XXX.XXX.XXX 255.255.255.255 Vlan1 permanent
ip route XXX.XXX.XXX.XXX 255.255.255.255 XXX.XXX.XXX.XXX permanent
!
ip flow-top-talkers
top 10
sort-by bytes
!
ip http server
ip http authentication local
ip http secure-server
!
ip access-list extended voip-traffic
permit tcp any any eq 5060
permit udp any any eq 5060
permit tcp any any eq 4569
permit udp any any eq 4569
!
dialer-list 1 protocol ip permit
snmp-server community XXXXXXXXXXXX RO
!
control-plane
!
line con 0
no modem enable
line aux 0
line vty 0 4
login
!
scheduler max-task-time 5000
end
[/code]I believe that I have assigned 30% of the bandwidth to IAX both inbound and outbound. Am I right or is it a complete mess ? |
|
deepblackmag
join:2004-12-27
00000
| I dont see where you have applied the policy-map voip-priority to an interface.
I would enter the following commands:
|
|
UxBoD
@bt.net
| reply to UxBoD
I changed the policy-map and did not re-apply it when I took the config dump  With that said does everything else look correct ? any advice on how I could make it better. As I set the priority for the voip-class I presume all other traffic will battle for the bandwidth on a first come first served based. As I run a mail/web server and my own DNS would I be better setting up a second class for those services aswell ? All help greatly appreciated. |
|
deepblackmag
join:2004-12-27
00000
| QOS is one of those personal preference things. If you look at what managed services puts on customer equipment, generally its something along the lines of:
class priority-stuff
match dscp ef
policy-map whatever-out
class priority-stuff
priority percent 100
class default-class
fair-queue
and thats it. They dont waste time messing around with with af1x, af2x, af3x, etc. After you use those and chop up the available bandwidth for a T1 for example (or a smaller ckt) it really doesnt make sense to allocate 16kbps to some class thats poorly defined anyways.
My usual approach would be to priority queue latency sensitive traffic, and fair-queue the rest. The other consideration is that usually QOS maps poorly onto adsl, and if this isnt a business connection the carrier will most likely strip off the tag. Also the upstream device will probablly not respect any inbound tags such as from your SIP provider. So if you are downloading a large file, voip traffic returning to your router could be delayed because there is no cooresponding policy-map (or equivilant) on the service provider edge device. |
|
UxBoD
@bt.net | reply to UxBoD
Thank you very much for your help it is appreciated. |
|
