7 Oct
2024
7 Oct
'24
2:30 p.m.
On Oct 6, 2024, at 7:13 PM, Johnny Billquist
<bqt(a)softjar.se> wrote:
The 16 bytes of optional data at connect and disconnect time can be generated by both
sides, and read by the other side optionally.
I don't know how TOPS-20 do things around this, but here is what I know from RSX:
When a connect request is sent, the request can include up to 16 bytes of data. The
process that receives the connect request can read this data out, even before accepting
the connection.
...
NICE use it to inform which version of the NICE protocol is used, so that other other
side can understand and also adjust. It's a sort of negotiation going on for this one,
and TOPS-20 *must* be implementing it there, so there is one place you should be able to
find something.
Yes, the typical use of connect data is for version number negotiation, which is a common
feature of DEC protocols. In that case, the connect confirm data contains the negotiated
version number -- the lower of what the two endpoints support. Occasionally something
else appears, for example in the MIRROR protocol where the connect init contains no data
and the connect confirm reports the max loop message size the mirror responder will
handle.
I'm not so sure of disconnect data; it might carry the version number of the sender if
a connect init is rejected due to version mismatch. The NICE spec would be expected to
say such a thing, but it doesn't.
paul