Hi all, I am just doing to bandwidth allocations for different types of traffic and have some questions. As I understand it, the measuring interval (T) = Bc/CIR, and every interval T a number of tokens equal to Bc is added to the bucket. If you do some basic sums then you'll find that say your CIR is 228kbits/s, then in any 1 second period the same number of tokens is added to the bucket, regardless of the conformed burst (Bc) value allocated. The main difference comes in the number of token allocated in teh time interval. So the lower the Bc is, the smaller T is and then smaller the number of tokens given to the bucket. Conversely, the larger Bc is, the larger T is, and the larger the number of tokens given to the buck. What you can't do is increase the number of tokens given in the same time period without increasing the CIR.
Enough of the theory! My question relates to whether anyone knows in pratice what sort of time periods are need for G.723.1 codec traffic. i.e. when the IP packet arrives, is the size of the packet such that it needs more tokens for delivery, and therefore a larger Bc, or is the rate at which the packets arrive so small that the Bc needs to be smaller, and there will be enough tokens within time T? Some examples: CIR=228kbits/s Bc=10kbits --> T=.0439sec, number of tokens added in T= 10 CIR=228kbits/s Bc=50kbits --> T=0.2193sec, number of tokens added in T= 50 So, which would be better here, a longer time period before more tokens are added here, or a shorter time period before fewer tokens are added? for this codec, the rate is 6.4kbits/s, so: (6.4*2)*8 = 102.4kbits/s (2 for full duplex conversation, 8 conversations at once) 102.4*0.0439sec = 4.495kbits/T We added 10kbits to the bucket, so there is heaps available, not withstanding the CIR allocation. SO in theory we could make the CIR smaller. If anyone can see here if I'm going wrong, then feel free to comment. cheers, Matthew. Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=56861&t=56861 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
