IP QoS issues

["Constantine Protopapas" <wiztech at cmpnetmail.com>]

Is QoS on TCP/IP reliable enough for applications that are
bit-rate-sensitive (like real-time video and toll quality voice)?Certainly
the IETF MPLS specification is a move towards the right
direction, but it's not yet ready. Meanwhile, vendors like Cisco offer
proprietary solutions, which further confuse the scenery, while ATM is  here
with standard QoS. However, TCP/IP is so popular that ATM is going to find
it hard to penetrate the enterprise WAN; but, as telcos move from
traditional technologies to packet- or cell- switched networks, the protocol
of choice is
 ATM. So, what will eventually happen on the "WAN" side would be that ATM is
going to be deployed as the backbone with TCP/IP (or IP over ATM or IP over
SONET/SDH) on the branches.
On the "LAN" side, there is a dispute going on about which protocol is going
to dominate the market; Gigabit Ethernet or ATM. Gigabit Ethernet it's based
on a proven standard, but there are some unresolved issues (like the spec
for copper). Also there is no built-in QoS in the protocol and this is a
major drawback. On the other hand, ATM, although is a (relatively) brand-new
protocol, offers built-in QoS (CBR) and doesn't require any change on the
implementation either on the LAN side or on the WAN side of a network.
However, ATM is very complicated and the standards for it are not completed
yet and as a new technology still has some kinks to be worked out.
As I see it, from my point of view and my experience so far( I am a
systems/network engineer working in an Integrator in Greece that represents
Newbridge Networks), ATM although is not the "panacea" for the applications
requiring QoS, has more built-in features towards that end, so in
conjunction with IP, they will constitute the next generation Internet.

PS: I use the term "Internet" as a broad term for TCP/IP networks.
PPS: I am putting the terms LAN and WAN in double quotes, because of the
intermesh that exists.

 Constantine Protopapas
 e-mail: wiztech at cmpnetmail.com
 	   wiztech at hol.gr

 "...I've seen the future; it's digital..."