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New Member

Cisco 1720 connection using serial port

I have a problem. I have a network on board a vessel, the network is fine and I can ping the Router. However the router is connected to a Skanti Sat B which has a 9 pin connector. I ahve used the 60 pin to 25 pin lead supplied by Cisco and a standard 25 to 9 pin adapter. The Sat B also has an in-built default modem. Using the Router I can get upto 64K on this connection. However when I ping the ip address at the other end off the sat b connection the sat B just sits there and does nothing. I've checked with the documentation that came with the 1720 and every thing seams o.k. I can ping to the ethernet but can't connect to the outside world. Hope someone can give me a script for serial connection and dialer, or pointers. Router has a sync/async card installed.


Adam Webster Senior Marine Engineer

New Member

Re: Cisco 1720 connection using serial port

Am I correct in assuming that your goal is a Dial on Demand Routing (DDR) scheme? There are hundreds of pages of documents and examples on CCO for setting up DDR. You need to figure out what makes that Sat-B dial. I have done IP over INMARSAT in the past. I have found that DTR Dialer is often the only choice. But you will need to find out if that is sufficient to cause the Sat-B to dial.

New Member

Re: Cisco 1720 connection using serial port

To start of with DDR is the option I am trying for. However the 1720 does have a scheduler built in but I havnt figured that out yet. I have successfully set up a Cisco using a 25 way DTE servral times with no hassels. I would have thought that if I bought a 25 TO 9 pin converter (standard) it would have been the same pin layout, its either that or my script is wrong.

New Member

Re: Cisco 1720 connection using serial port

So you are using dial scripts. Which probably means you are using async. I have set up 1720s for async as recently as a few days ago. Make sure you have:

'physical-layer async'

'async default-routing'

'async mode dedicated'

on the interface. The last one is key. Without it, the interface just sits there waiting on some type of input in order for it to determine what its role is.

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