DEMSB replacement

[Sanjoy Paul]

Hi ,

We have a DEMSB connected to the network which is accessed by an ALPHA 2100 server . The DEMSB is connected to a X.25 switch on the other side . The X.25 network is going to be replaced by a TCP/IP network .Please suggest me a device which can be used to replace the DEMSB in the TCPIP environment .

Thanks in avdance.

Sanjoy

[Ian Miller.]

There is insufficent information supplied to answer your question. What software is the DEMSB running and what job was it doing?

WAG - If it was helping to provide a DECnet over X.25 WAN link then replacing it with a IP router and configuring DECnet over IP would be the way forward.

[Sanjoy Paul]

Hi Ian,

Thanks for your reply . Basically , the DEMSB is in the same network with the Alpha server . It acts as a PAD (Protocol Assembler/de-assembler) , the host VMS server communicates with the DTE on the other side (where a Windows server is connected) via this DEMSB.


DEMSB info is:

ROM Firmware Version: 28-OCT-1988 12:36

Processor State: *RUNNING*
Software state : Running

Best regards,

Sanjoy

[Robert Brooks_1]

Well, it's certainly possible that you need no additional hardware. You may, however, need an application redesign, rewrite, or modification, depending on how isolated the network-knowledgeable components are.

If you're just using X.29 (for example), you may find telnet to be a suitable replacement.

-- Rob

[Colin Butcher · Accepted solution]

Replacing X.25 with TCP/IP is a non-trivial task. You will probably need to look at how the application works at both ends and then decide how to re-design parts of the applications and also the underlying systems and networks infrastructure. It certainly won't be as simple as swapping a DEMSB for something else.

If you've not much experience of designing applications and infrastructures then I strongly encourage you to bring in outside help in order to do the job well.

Please bear in mind that this system is likely to be doing an important job and could well be seen as a high-risk item to make changes to - otherwise it would have been changed a while back.

Cheers, Colin (www.xdelta.co.uk).

Systems archaeologist (where are the bodies and what _were_ they smoking when they designed this?).

[JohnDite]

Hi Sanjoy,

there is company called Funkwerk that offers such a beast.

see http://www.funkwerk-ec.com/scripts/info_cd/en/solutions/50-ss_tcp_to_x25_gw_1-en.pdf

Whether it will fit your requirements is another matter. As you may well realize, X.25 is segment oriented whereas TCP is streams based, so it depends how the data is sent by your applications. However Funkwerk seemingly have done various projects at ALCATEL(?) and/or Deutsche Telekom using this solution,
so parts of it must work.

In your configuration you could keep your DEMSB and connect to one of these Funkwerk Gateways via X.21 or if you want to get rid of the DEMSB you can access the Funkwerk Gateway from the Alpha system via LLC2 or XOT.

The gatewaying solution is I think available on their BINTEC X4000 and X8500 family of routers.

It's possibly worth investigating further.

I've dealt with these Funkwerk Gateway/Routers for the last few years, as they have often been used in this part of the world to migrate customers from an X.25 Service Provider to running X.25 over ISDN. The Funkwerk Gateway/Routers do an X.25 to XOI (X.25 over ISDN) mapping such that you do not have to change your X.25 infrastructure.

If you need more info let me know.

[Colin Butcher]

John,

That looks like a useful device. I've not had the need for one (stuff has usually been redesigned and advantage has been taken of things like SSH), but I can see the possibilities.

Cheers, Colin (www.xdelta.co.uk).

[Sanjoy Paul]

I found the answer of my quary.

[JohnDite]

Hi,

glad to hear that you found your solution. It would be great if you could share it with the rest of us.

Thanks
John