Actually, that web page is correct. Tc = Bc/CIR, and the answer is in seconds. If you get an answer such as .125, that is 1/8th of a second, or 125ms.
At work we use a Bc of 5120 on 512k links. 5120/512000 = .010, or 10ms, which is the recommended interval. It all depends on what units you're using, as well. Perhaps he is using different units of measurement. Regards, John ________________________________________________ Get your own "800" number Voicemail, fax, email, and a lot more http://www.ureach.com/reg/tag ---- On Tue, 18 Dec 2001, Steven A. Ridder ([EMAIL PROTECTED]) wrote: > I believe the true calculation for the interval (Tc) is Bc=CIR (Tc/1000). > This web page over-simplifies it. I have read in varoius sources > (Intergrating Voice and Data Network, and from Wendel Odom himself, that > it's actually the above calculation. I have other problem wih CCO web > pages > also, especially Dialer Watch, CBAC, etc. I think Cisco is too big to > manage :) > > > ""John Neiberger"" wrote in message > [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > > I only see two examples on that page that are different. The first is > > on a 56k link, Bc=1000 and CIR=56000. Bc/CIR = .0178, or basically > > 18ms. I know that's higher than the recommended 10ms, but perhaps > there > > are drawbacks to lowering the Bc below 1000 that I'm not aware of. > > > > The other example is on a 256k link. Bc = 1000, CIR = 256000, so > > Bc/CIR = .004, or 4ms. This will set your Tc to the minimum of 10ms, > > IIRC. > > > > Regards, > > John > > > > >>> "Steven A. Ridder" 12/18/01 5:22:56 PM >>> > > The bc info for the Frame-Relay traffic shaping info on that page is > > wrong. > > One should always target Bc to get a Tc of 10ms, but the config > > examples are > > more like a Bc of 36.4. So you have the serialization delay time at > > 36.4, > > but optimally you want 10ms. The packets will be going out at 10ms > (or > > less > > cause fragmentation ias correct) but the time interval the router uses > > is at > > 36.4ms. > > ""John Neiberger"" wrote in message > > [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > > > Here is another link that deals with WAN QoS, including some items > > that > > > might not occur to you such as sizing the interface transmit ring. > > > > > > > > > http://www.cisco.com/univercd/cc/td/doc/product/voice/ip_tele/av vidqos/qoswa > > > > n.htm > > > > > > > > > HTH, > > > John [EMAIL PROTECTED] Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=29606&t=29559 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
