TCP/IP over Frame Relay

TCP/IP over Frame Relay

Post by Kevin Cheven » Thu, 25 Jun 1998 04:00:00

Hi all

I'm considering "jumping ship" from Interactive UNIX SVR4, which I have
currently running on Pentium based test environment (Tekelec Chameleon),
to a more "interesting" OS, namely Linux.

I know all of you will say "Do it, do it, just dooo it."

But I need to know if the this change of direction will take me to where
I want to go. Given that I'm going nowhere with Interactive UNIX.

The problem is I have been given is to produce a test environment to
enable functionality validation of a piece of telecoms hardware.
The main features are that it must

1. Allow an app to talk via TCP/IP over the Frame Relay.
2. Allow the same app to talk directly over the Frame Relay,
different DLCI's.
3. Receive data/config etc over an normal LAN connection.

The problems are with features 1 & 2.
The current proposed solution is to write a device driver for Linux
which would be "attached" to the bottom of the TCP/IP stack.

From this DD the TCP/IP packets could then be sent directly to an
interface card.

There are 2 schools of thought as to the structure of the device drive
1. Make it look like a standard ethernet card.
2. Make it look like a tty driver and use slip to make the link from the
bottom of the TCP/IP stack to the driver.

The app would also connect directly to this DD.

My question are:
Does anyone have any experience on similar requirements?
Does anyone know of any HDLC card with X21 connection for the Frame
Relay link and suitable Linux Support?

As I'm a "New kid on the block!" please forgive if this is not the
right place for this request.

Kevin Chevens


1. TCP/IP Printing Problem w/HP JetDirect Across Frame Relay WAN

We're printing across our Frame Relay WAN link from Seattle to Denver to an
HP4050 w/internal Jet direct installed from IBM AIX 4.3.2. Works well most
the time. Denver called to say their jobs stopped printing. AIX said the
current job was still 'printing' and was partially completed. When Denver
cycled power on the HP 4050, the print job resumed printing. Since this has
happended before, I poked around a bit and saw the WAN ping times were then
about 1.5  - 2.5 seconds with 2 out of about 40 packets actually reported as
being lost. PING is usually about .25 seconds, so I'm suspecting TCP/IP
problems (timeouts??).

Since I'm currently stuck with poor line performance (for various reasons),
what can I adjust with the TCP/IP settings to maybe be more forgiving of our
periodically slow lines??

Any configuration options with the Jet Direct themselves to make them more
'forgiving' of poor lines / performance??

2. uw imap tools for redhat 7.1 ?

3. TCP/IP (Frame Relay) to X.25?

4. NIC not recognized - eth0: unknown interface: No Such device

5. Compress TCP/IP frames ??

6. acer aspire 1362LC: chipset via K8N800

7. What frame types for TCP/IP?

8. Routing table confusion