Many boxes are able to reorder packets. If packets arrive too late to be inserted into the conversion stream, they are dropped. One dropped packet in a sequence can usually be 'hidden' or 'faked' by the codec. When more than one packet is missed in sequence, it becomes noticeable to the listener. Ray Burkholder

-----Original Message----- From: Leo Bicknell [mailto:bicknell@ufp.org] Sent: February 10, 2003 14:44 To: nanog@nanog.org Subject: Re: VoIP QOS best practices

In a message written on Mon, Feb 10, 2003 at 01:19:08PM -0500, chaim fried wrote:

...

happens). There is no reason to implement QOS on the Core. Having said that, there still seems to be too many issues on the tier 1 networks with pacekt reordering as they affect h.261/h.263 traffic.

So what's the real problem here? Are the VOIP boxes unable to handle out of order packets? Do the out of order packets simply arrive far enough delayed to blow the delay budget? What percentage of reordered packets starts to cause issues?

-- Leo Bicknell - bicknell@ufp.org - CCIE 3440 PGP keys at http://www.ufp.org/~bicknell/ Read TMBG List - tmbg-list-request@tmbg.org, www.tmbg.org