From: Felice Russell (felicear@sbcglobal.net)
Date: Wed Jun 30 2004 - 14:35:34 GMT-3
I have been trying to comprehend whether Custom Q and Class-based Q are
interchangeable? Class-based is much easier to configure without all the
tricky math but will it meet the requirement? I thought the ultimate goal of
CQ was to allocate a percentage of bandwidth to said queue so each queue
receives equal treatment overcoming the queue starvation problems found with
PQ. So, that being said, with CB the ability to allocate a percentage of the
bandwidth is readily available the only two things seem to be missing and I
am not certain how important the first is ... 1) the average packet ratio 2)
Cisco's blessing. Thoughts? Am I missing something key here?
Additionally, I found some seemingly conflicting inforation regarding the
calculation for Bc
http://www.cisco.com/en/US/tech/tk543/tk545/technologies_q_and_a_item09186a0
0800cdfab.shtml
Normal Burst = CIR [BPS] * (1 byte)/(8 bits) * 1.5 seconds
Note: 1.5 seconds is the typical round trip time
Excess Burst = 2 * normal burst
Where "The Frame Relay committed burst size is specified within a map
class to request a certain burst rate for the circuit. Although it is
specified in bits, an implicit time factor is the sampling interval Tc on
the switch, which is defined as the burst size Bc divided by the committed
information rate (CIR)."
Which means: Tc = Bc/CIR
Or
Tc * CIR = Bc
http://www.cisco.com/en/US/products/sw/iosswrel/ps1824/products_command_refe
rence_chapter09186a0080087bcd.html#xtocid106825
So in a THE lab situation which calculation would be correct?
Thanks
Felice
This archive was generated by hypermail 2.1.4 : Sat Jul 03 2004 - 19:40:53 GMT-3