08-18-2008 07:13 PM - edited 03-15-2019 12:42 PM
Hi All,
I try to do QoS on my routers for VoIP, but i can not overcome traffic congest issue.
I only have 256 kbps bandwidth and would like to reserve 128 kbps bandwidth for voice only. Emails or anyother traffic should not touch that bandwidth. Can I do that kind of things on cisco 1700 Router with IOS 12.3X?
08-18-2008 07:53 PM
if have ur voice marked corectly which is by default marcked with dscp ef or 46
i will give u to ways
if u sure about marking do the following class map
class-map voice
match ip dscp ef
if not sure and u have ur voice i deffrent vlan that datat let say vlan 20 and vlan 20 ip range is 10.1.1.0 /24
do this class-map
ip access-list extended VVLAN
permit udp 10.1.1.0 0.0.0.255 any range 16384 32767
class-map voice
match access-group VVLAN
now creat an policy map
policy-map voice-policy
class voice
priority 128
class class-default
fair-queue
now just apply it on ur outise interface
like
interface [urport numner]
service-policy output voice-policy
the above conifg put the voice in piority queue LLQ so it will reserive 128 in case of conjestion and will be serveced first too
this is the ideal config for voice :)
just make sure from the marking i have put to cases for u of how to match the voice traffic
use either one or whatever way u want as long as u match the right traffic
for exra setup if u want u can match and reserv bandwith for call signaling aswel
like for example
ip access-list extended call-signaling
permit tcp any any range 1719 1720
permit tcp any any 2428
permit tcp any any range 2000 2002
then add it to ur policy like
policy-map voice-policy
class call-signaling
bandwidth 30
the above just reserve 30 Kb for call signaling but not put in priority queue!
and all the above classes will use more than the reserved bandwidth in case no conjestion and there is avalable bandwith
good luck
please, if helpful rate
08-18-2008 08:46 PM
Hi,
So the actual config is
policy-map voice-policy
class voice
priority 128
class class-default
fair-queue
interface [urport numner]
service-policy output voice-policy
Do I need to do VLAN in my Router?
advice me. I am not too good for Routers.. :)
thanks.
08-18-2008 08:55 PM
ok
before we give priority or reservie bandwidth to a voice traffic we have to identify the voice traffic from other traffic
normalyy the switch connected to the phone dose this with the cisco phone
the swithc trust the cos coms from the phone and the cisco phone by default mark voice traffic with dscp ef or layer two cos 5
if now u have to have saparate vlan for voice and data
if u dont have it will work but here the problem it will be harder to clasifiy the traffic
so just give me an idea how is ur network is connected what and hwo they get IPs are all in the same IP network i mean phones and PCs
and do they connect to switch or how they connect to ur router
just send me these detaisl to let me help u more
thank you
08-18-2008 11:09 PM
OK.
I am using IP PABX that's connected to 1841 DSL Router which use for Internet.
After that router i have local 1760 cisco Router which is connected from singapore to Yangon via 256 kbps leased line.
From Yangon router, I connected ATA devices that one Ethernet input and two Rj11 output which we can connect with telephone handsets.
the traffic is between yangon to singapore two 1760 routers.
thanks,
08-19-2008 04:31 AM
ok can just please tell me the voice traffic from where to where go ?
is the IP PABX connected to the local 1760 router?
do u have any voice diial peer configured if yes where ?
i just wanna know ur traffic path for voice
and dose the pbx has IP or range of IPs
sorry but i just wanna know more details to give more accurate answer
08-19-2008 07:59 PM
IP-PABX is connected with 1841 Router.
then fe cable connected to SG 1760 then connected to YGN 1760 with 256 leased line from sg to yangon.
As it is IP Base PABX, i really do not need to configure dial peer config. I just need to open some ports for voice traffic.
Voice can communicated once IP network is there.
Yeah I need to assign one IP for PABX. 192.168.30.x like that.
Thanks,
08-19-2008 08:26 PM
ok cool
lets say the IP PABX ip range is 192.168.30.0/24
first we gonna match the traffic from the PABX then mark it i will mark and match all traffic from the PABX
u can marck only voice RTP traffic by useing the following ACL:
access-list 100 permit udp 192.168.30.0 255.255.255.0 any range 16384 32767
but the following one will match evry IP traffic from the PABX:
access-list 100 permit IP 192.168.30.0 255.255.255.0 any
class-map PABX
match access-group 100
plolicy-map PABX-marking
class PABX
set ip dscp ef
now u have to apply this policy to the interface connected to the PABX on the SG 1760 fe
like
interface fe 0/1
service-policy input PABX-marking
now after the PABX traffic enter this interface it will be mark as dscp ef (46)
so for the outbound policy we cam match it easily
for bandwidth reservation do
class-map voip
match ip dscp ef
policy-map voip
class voip
priority 128
class class-default
fair-queue
now go to the lease line interface let say serial 1/1 for example
interface serial 1/1
service-policy output voip
and becareful in the first ACL u have to match the traffic exactly regarding the right IPs
good luck
please, if helpful Rate
08-19-2008 08:45 PM
Hi,
Appreciated for your reply.
But PABX is connected with 1841 Router with FE port. Not to 1760.
From 1841 to 1760 I have another FE port connected. then SG 1760 serial to Yangon 1760 Serial.
I want to draw the diagram here. :)
Thanks a lot.
08-19-2008 09:00 PM
then put the input marking class-map, policy map and ACL on the 1841 router and apply it to the interface connected to the PABX fastethernet in the input direction the same
so now u gonna make the marking config on the 1841 and the resrvition on the 1760
did u got ??
if u need any more details post it here
good luck
if helpful Rate
08-19-2008 08:58 PM
Ok,
Can I do like this?
Just forget about 1841 Router that connected to IP-PABX and
access-list 100 permit udp 192.168.30.0 255.255.255.0 any range 16384 32767
access-list 100 permit IP 192.168.30.0 255.255.255.0 any
class-map PABX
match access-group 100
plolicy-map PABX-marking
class PABX
set ip dscp ef
interface fe 0/1
service-policy input PABX-marking
All above config will be configured in 1760 router which has fe connection to 1841 router.
Then,
class-map voip
match ip dscp ef
policy-map voip
class voip
priority 128
class class-default
fair-queue
interface serial 1/1
service-policy output voip
to same SG 1760 router serial.
How about like that?
I also need to that config at Yangon end rite?
08-19-2008 09:28 PM
sure u can and very good
aboyuut he other site
u need to do marking on the traffic coming from the phones or ATA mark it the same idea and give it priority on the outbound direction on the remote 1760 router
this will be two way
good luck
hope this helpful :)
08-21-2008 12:36 AM
My plan is to add one more fe port only for ATAs in Yangon router.now it is mixed with data and implement what u advice.
will let u know when i finished !!
Thanks a lot.
u r the man.
08-21-2008 06:53 PM
great explanation there. nice and to the point
09-10-2008 04:59 PM
Hi Man,
:( the config is not applicable for me.
Bandwidth is not actually reserve and voice quality is the same.
I changed my network design like
PABX--> 1700 Ethernet-->1700 Serial(SG) --> 1760 Serial (YGN)--> 1760 Ethernet --> two ATAs.
Now pabx n atas are in different ethernet port of each routers.
any more advice?
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