Re: [RPRWG] MAC Question
Ray,
hopefully I will not step on anyone's toes in giving this
answer.
there are multiple approaches to this issue and there are
trade-offs with each. However, everyone agrees on destination
stripping of uni-cast packets and the need to allow multiple
nodes on the ring to transmit simultaneously. Also,
no one is (yet) proposing a token mechanism similar to
.5.
some people support a store and forward paradign on the ring
where all packets are completely buffered on the transit
path.
there are at least 2 camps using the term cut-through to mean
somewhat different things. they do agree on begining to
transmit a transit packet as soon as possible. The difference
is in the definition of as soon as possible and the size
requirement on the transit buffer.
cheers,
mike
Ray Zeisz wrote:
>
> I am following the .17 group from afar, but I have a question:
>
> Is it acceptable for each node in the ring to buffer up an entire packet
> before forwarding it to its neighbor? Would the latency be to great if this
> were done? Or is the .17 direction more along the lines of 802.5 where only
> a few bits in each ring node are buffered...just enough to detect a token
> and set a bit to claim it.
>
> Ray
>
> Ray Zeisz
> Technology Advisor
> LVL7 Systems
> http://www.LVL7.com
> (919) 865-2735
--
Michael Takefman tak@xxxxxxxxx
Manager HW Engineering, Cisco Systems
Chair IEEE 802.17 Stds WG
2000 Innovation Dr, Ottawa, Canada, K2K 3E8
voice: 613-271-3399 fax: 613-271-4867