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New Member

QoS for Telnet over PPP T1

We have a bandwidth issue with one of our locations. It's connected to our main office through a PPP T1. The main application that is being used is telnet. We have several application servers that are centrally located at our main office and when reports are ran, the T1 is bogged down and slows the telnet users down so much, there connection comes close to dying. Upgrading the line or moving the servers is not an option. The reports don't run every day, but when they run, they are a pain. I've been trying to research a way to dedicated a 10% priority for Telnet applications, but have not had any luck. I've looked at the IP RTP commands, but I'm not sure if that is what I need. If there is someone that could suggest anything or know of a good spot to look, or could even give a sample config, I would greatly appreciate it. If there are any other suggestions on how to solve this, I'd appreciate those as well.



New Member

Re: QoS for Telnet over PPP T1

ok you want to apply QoS. there's mainly 2 types of QoS stratégies:

-priority queuing: if trafic A is more important than traffic B then

while trafic A exist forward trafic A & ignore traffic B.

-custom queueing: traffic is forwarding according to pourcentages.

i think you want to make the second type.



access-list 101 permit tcp any any eq telnet

queue-list 1 protocol ip 5 list 101


here we caracterise telnet traffic by access list 101

then we put such traffic in queue 5.

make the same thing with other types of traffic (use the same queue-list (number:1) but with different queues : 6, 7,...16.

apply queue-list 1 to interface S0

router(config-if)#custom-queue-list 1

now comes the difficult step:

you must estimate the max records by queue and how many octets the router must forward before going to the next queue.

the commands r:

queue-list 1 queue 5 limit X

queue-list 1 queue 5 byte-count Y

all the prob is in choosing X & Y does any one has idea how to estimate them?

New Member

Re: QoS for Telnet over PPP T1

What version of IOS? Later version of IOS have Telnet already prioritized within WFQ, which is the default for e1 and below. If you have a pretty late version of IOS, I can give you a config with a high priority of telnet with CBWFQ or LLQ. There you'll be all set.

Actually I'll type it:

class-map telnet

match access-group 101

policy-map telnet

class telnet

priority 154

service-policy output telnet

New Member

Re: QoS for Telnet over PPP T1

I'm running 12.1 IOS.

Remote Location:

This is on the 2600

C2600 Software (C2600-IS56I-M), Version 12.1(11)

Main Office

This is on the 3500

3600 Software (C3640-I-M), Version 12.1(2)T

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