>I'll likely be adding SunLink X.25 (for Solaris 1.0 - aka SunOS 4.1.3) to an
>existing application, and could use some answers from anyone with experience
>using it. (I need to estimate the task, before purchasing the software.)
You'll probably have to upgrade your Solaris to 2.2 or 2.3 to run the
most recent version 8.0.
Quote:>I'm adding this to an application which currently has a dialup (modem)
>interface between a client and server. It uses standard open() &
>read/write() functions, then sends commands to the modem and communicate
>to the other end. Now the application must communicate across an existing
>X.25 network, about which I know very little.
>My questions are as follows:
>- What kind of interface is there to SunLink X.25?
The X.25 API, which is from Spider Systems, comes with two interfaces;
NLI and streams, of which only the latter will be supported in future
versions. The streams interface is really nice to program if you have
tried other X.25 APIs.
Quote:>- How do I establish my initial connection from the client & server?
>- Can I tell if the other end dies? (either the application or the
>connection) It's possible for the client&server to reverse roles, so I'm
>sure this could complicate things.
Unless you have a transport layer interface, you'll program X.25 on the
network layer, which consists of sending and receiving network primitives.
For instance, to establish a connection you send a connect request, which the
other end will respond to by either sending a connect confirmation or
disconnect indication block.
N_CONN_REQUEST -----------> N_CONN_INDICATION
N_CONN_CONFIRMATION <------ N_CONN_RESPONSE
If you're not familiar with the OSI network layer, I can recommend
Tanenbaums "Computer Networks", which describes all the OSI layers and
the network layer in particular. Don't expect much help from the
Spider manuals, they assume you're already familiar with X.25.
The only bad thing I have to say about Spider X.25 for Solaris is that
it costs more than a SparcClassic.