1822 vs 1822L Survey


klem@BRL.ARPA
Fri, 5 Sep 86 16:03:59 EDT


Subject: imprecise DDN X.25 specification?
Newsgroups: mod.protocols.tcp-ip
Distribution: usa
To: tcp-ip@sri-nic.arpa
Keywords: DDN X.25 CDC

We have a contract with CDC to build and install an interface from a CDC
Cyber 750 running NOS to a MILNET IMP. The contractors attended a 3-day
TCP/IP Vendor Workshop in Monterey last month. They came away from the
meeting with lots of questions. Can anyone answer the concerns that were
surfaced at the meeting (see below for the contractor's questions)?

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It was stated that the contractor can be implementing X.25 in agreement with
the contract specification, pass the DCA Qualification Test and not be able
to communicate with the IMP. This is a result of the imprecise DDN X.25
specification and the incompleteness of the X.25 Qualification Testing.

One X.25 issue that was discussed was the X.25/1822 incompatibility on the
network. It is our understanding that the government has developed hardware
and software solutions and has the situation under control.

Other issues that could affect the CDC interface to the IMP include:

1) CDC X.25 does not establish a virtual circuit for each and every local
network destination host and corresponding precedence.

2) CDC will provide the destination address to the IMP through the IP
header, as opposed to the X.25 header.

3) CDC will not map an IP address into X.25 and vice-versa.

Is it true that any or all of the above issues will create problems in the
CDC interface with the DDN?

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Thanks,
George Klem <klem@brl.arpa>



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