🚀 go-pugleaf

In <1992Oct15.213513.4034@chsun.chuug.ch> mpeters@pax.eunet.ch (MBX Michael Peters) writes:

>Can somebody give me a one line definition of what the difference between
>X.25 and X.75? As near as I can gather (I don't have CCITT red books) it 
>lies in the fact that X.75 is a network to network X.25. 

You win the teddy bear. :-) Yes, X.75 was designed to operate
between two packet networks while X.25 is user-network. Now it
has been a few years, but X.75 includes a multi-link procedure
at layer 2 (link level) which is basically an inverse mux. With
this, the network operators can combine several data links to
increase throughput, and also make the link more reliable.

>What I really need to know, is there any appreciable difference besides the
>international calling procedure in X.75?

As I said, haven't looked at X.25 since 1984, so maybe they have
added the multi-link procedure to it as well, but that was the
only basic difference in addition to the calling.

>2nd question is methods of throughput computation. If you've got a router
>with say 20 ports at 19.2kbs max. What is the throughput? (WAN router for
>X.25, SNA SDLC, and ASYNC, for example) 

>I've heard some people say 650pps. Others say 16 ports at 64kps is 1000. Is
>it just the packet size you pick? And, if so, what is typical packet size
>for the above example (64 bytes seems way to small)? 

That is rather small, when we started DATApac in Canada there were
two sizes. 128 bytes was for international (cause that was the CCITT
setting) and 256 bytes was the national and normal size. Interestingly
enough, that is why the ISDN D-channel is set at 260 bytes - so that
it can take a 256 byte packet plus the 4 byte header.


>Okay, so it's more than one quetion, but hey..

>Oh, don't flame the sig.. I just wanted to try it out okay. (4 line, I know.)

>Thanx in advance, 
>Mike.

>BTW If anybody knows a group that these types of questions might be more
>appropriate let me know that too. B`> (I broke my nose last week!!)

Sorry about your pretty bipe :-)

Bob