we are going to need an expert opinion on this. SRND says not to exceed 20 ms delay. but what if the the difference between port speed and CIR is big that the delay value according to the calculations go higher than 20 ms???
On Fri, Apr 4, 2008 at 11:13 AM, Devildoc <[EMAIL PROTECTED]> wrote: > What Jonathan wrote below about the fragment delay for 768Kbps is 10ms and > for 384Kbps is 5ms are only true if those delays were based on the port > speeds. > > However, I think Jason was asking for the fragment delay for a CIR of > 384kbps and the port speed of 768kbps. In this case, Jason's calculation of > 20ms for fragment delay is correct. Fragment delay is calculated based on > port speed and NOT based on CIR. > > JD > > > > Date: Thu, 3 Apr 2008 00:42:16 -0500 > > From: [EMAIL PROTECTED] > > To: [EMAIL PROTECTED] > > CC: [email protected] > > Subject: Re: [OSL | CCIE_Voice] MLP serialization delay > > > > > Serialization delay is a function of how long it will take to get X > > bits onto the wire at speed Y > > > > And is simply X/Y > > > > So, a 1500-byte ping will take 214ms to be put on the wire at a line > > speed of 560000 bps > > > > (1500*8)/56000 = .214 > > > > So, you list the speed of the circuit.... 768000 > > > > The fragment size ... 960 > > > > So, (960*8)/768000 = 10 ms > > > > So, 384k would equal 5ms > > > > > > > > Jonathan > > > > On Wed, Apr 2, 2008 at 8:29 PM, jason sung <[EMAIL PROTECTED]> wrote: > > > Can someone confirm my calculations? I am trying to calculate delay > based on > > > port speed and CIR. > > > > > > Port speed: 768 > > > CIR: 384 > > > > > > fragment size = 768 *10/8 = 960 > > > > > > delay = fragment size *8/ CIR > > > = 960*8/384 > > > = 20 ms > > > > > > 20 ms sounds too high though.... > > > > > > TIA > > > ------------------------------ > Pack up or back up–use SkyDrive to transfer files or keep extra copies. Learn > how. >
