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Community Member

Connect Tandem Bisync to IBM Ethernet

I need to build a connection between a new Tandem that speaks only

Bisync, as we configured it, to an IBM that speaks only Ethernet. The

Tandem does not speak the "EP" flavor of Bisync, but the NCP or VTAM

flavor, which is called Polled Bisync. The IBM speaks only Ethernet because

we did not purchase a 3745 controller, and do not wish to purchase one.

Third-party vendors are offering solutions, but they seem too bulky and

expensive. The circuit could look like this:

Tandem <--- BSC/LLC------------LLC/BSC<----IBM

"BSC/LLC" means Bisynchronous over Logical Link Control. In this example

Bisynchronous would be encapsulated or tunnelled in LLC. I know I said

the IBM could speak only Ethernet, but if we could find a solution for

Polled Bisync on the IBM side, that also might be helpful. We are wondering

about using two boxes, one that does BSC/LLC on the Tandem side, and

one that does LLC/BSC on the IBM side. We're also wondering if we can

use something as simple as one router and one cable. The circuit sketch

has arrows pointing left because the IBM must be the source or primary

in the data communications. The Tandem watches for a polling number from

the IBM, and when it sees the correct one, sends a message to the IBM.


Re: Connect Tandem Bisync to IBM Ethernet

Unfortunately Cisco only supports tunnelling bisync between 2 serial interfaces. There is no facility to convert to LLC.

Community Member

Re: Connect Tandem Bisync to IBM Ethernet

Hi Eddy,

Rona is correct that Cisco doesn't do BSC to LLC conversion. But we do have a BSC to IP conversion that just might be useful here. It's something of a long shot, so if you want to discuss it, we should take it off line. Send me a note, if you would like more information.

Rgds, Dan

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