Weighted fair queueing and available bandwidth

[j-cherrier]

I am working on a 512k fractional T1 and looking at the serial interface which is running HDLC with a BW of 512k, I see it is using the default weighted fair queueing.. In the show interface serial display I am seeing...

Queueing strategy: weighted fair

Output queue: 0/1000/64/0 (size/max total/threshold/drops)

Conversations 0/40/256 (active/max active/max total)

Reserved Conversations 0/0 (allocated/max allocated)

Available Bandwidth 384 kilobits/sec

I have been unable to find any documentation that explains why I am seeing 384K available bandwidth listed on a 512k connection. The BW on the interface is set for 512k. WFQ is running on defaults..nothing is configured or changed. Any ideas? Sources of info that would explain what I am seeing?

TIA..

[Erick Bergquist]

25% is reserved for routing protocols, and other router control traffic by default. You can change this with the 'max-reserved-bandwidth' option under the interface.

25% of 512 is 128, so 512 - 128 is 384.

[j-cherrier]

Thanks for the info.. Explains what I was seeing.....