Re: [9fans] Network design question

[dantes@vif.com]

vdharani@infernopark.com wrote:
>>- from the OSI point of view, the layers 4, 5 and 6 have a custom
>>protocol implementation: 9P.
> 
> 9p is similar to nfs protocol. the main difference is nfs is designed to
> serve regular data files and so it treats data in terms of blocks. 9p
> additionally takes care of device files and the data is treated as
> messages of variable size (max is 8192). and 9p messages are not cached.

Isn't it a bit more than NFS? From "The Organisation of Networks in Plan 
9", it seems it can also *do* messages and RPC, while AFAIK NFS is 
*using* messages and SUN RPC... Maybe I'm just plain wrong.

>>- 9P offers an interface at layer 5 (messages, local)
>>
>>- 9P offers an interface at layer 6 (RPC, local)
> 
> i am not sure if 9p can be treated like this. i guess it is pretty much
> the 4 layer tcp/ip with 9p sitting on top of tcp/ip. 9p is like nfs
> protocol and uses rpc mechanism.

Considering from your next answer that IL is a transfer protocol, can 9P 
be fully used on top of IL? (ie does it rely exclusively on TCP and its 
stream orientation?)

>>- a service does translation from 9P to TCP for external communication
>>(at level 4?).
>>
>>Where does IL fit in all this?
> 
> il is pretty much similar to tcp except that while tcp works in
> byte-stream mode, il wrok in message-mode.

OK, thanks for this input.

> thanks
> dharani

Thanks a lot
Jef