1. Voice is a "low burst rate" data in addition to other characteristics required such as low latency, jitter etc.
2. If you really want to think in terms of layers, voice is not layer 4 stuff, it is an application, just as video is. It might go down through presentation layer for say compression before being transported at layer 4 (udp/tcp/rsvp etc) and then encapsulating it into layer 3 packet (IP,IPX etc). 3. VoFR does not necessarily mean that IP is now out of picture and voice is directly being framed into FR. Mostly, IP is still there. FR, ATM, Enet are just media mechanisms. You can skip IP however if you switch a lot. Like frame relay switching or ATM switching etc. 4. DLCI is just locally significant, it is just a way to identify connections. Nadeem ====== landcai wrote: > Hi, Gang, > I have a small thing I am still clear about, even though I thought it over. > what's the difference between VOip over frame Relay and VoFR? Does it mean > that for Voip the voice is taken as the data regarded as layer 4 data, then > encapsulated in layer 3 ip,then further be encapsulated as layer 2 frame > relay frames. but for VoFR, the voice don't need to be encapsulated by > layer 3 protocol, and directly passed to layer 2 frame Relay network? > could you shed me light over it? I could not turn it over on my brain. Many > thanks, > ______________________________________ > > =================================================================== > PB@KCb7Q5gWSSJOd (http://mail.sina.com.cn) > PB@K7V@`PEO"#:GaKI6)TD#,A?Im6(VF,:CPEO"@4URDc! (http://classad.sina.com.cn/) -- ==================== Ishrat Nadeem Zahid CCNP Cisco Systems,Inc. Chelmsford, MA 01824 Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=35462&t=34947 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
