flexwan PA-8T default queue-limit

Unanswered Question
Jan 29th, 2009

HI. everyone.

We have got a Cisco 7609 Router included flexwan module with PA-8T port adapter.

Our plan is make a LLQ policy every serial line(about E1, T1)..

But, I would like know queue-limit every device.

for example.

C7304 defalut queue-limit is 64 no tuned

C3825, 7206 has default queue-limit 4096

However, C7609 included flexwan with PA-8T has queue-limit is max 330290 packet per class-map. there are no default value, It changes dependend other factor! What factor makes a variable queue-limit value?

Why C7609 has a large queue-limit? There are all Serial line(t1,e1,) but C7609 has large queue-limit value,

and Recomanded queue-limit, I know that it depends a site environment, right?

for example, if there are 64 packet in serial line, the queue-limit has upper value , if 1450 over, queue-limit has lower value, right?

or not, If there are recommanded value?

thank you

I have this problem too.
0 votes
  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 0 (0 ratings)
Paolo Bevilacqua Thu, 01/29/2009 - 04:51


In practice you will find that a reasonable queue limit on low speed circuits should not exceed, say 200 pkts.

Also as you noted different platforms have different memory due to their specific architecture. Note the flexwan had a distributed processing, the ISR not, etc.

Again generally speaking, having huge buffering space on serial cards should give you no advantage in setting a simple priority mechanism on a set of interfaces.


This Discussion