Chapter 6 - Async To Sync Ppp And Slip; Internet And Remote Access Ppp And Slip; Making Async To Sync Ppp And Slip Calls - ZyXEL Communications Omni TA128 User Manual

Chapter 6 - Async to Sync PPP and SLIP

Chapter 6 - Async to Sync PPP and SLIP

Internet and Remote Access PPP and SLIP

More and more Internet Service Providers are offering their services through dial-up
ISDN lines for higher data bandwidth. The equipment used at the service provider's
location are frequently ISDN LAN routers which, unlike terminal adapters, do not have
asynchronous capability. For this reason, terminal adapters that support only V.120 or
asynchronous protocol will not work with this type of equipment.
The Omni TA128 is able to convert the asynchronous data it receives from your
computer to synchronous format in order to communicate with ISDN LAN routers. We
call this process asynchronous to synchronous HDLC conversion. To simplify it, we call
it Async to Sync PPP (Point-to-Point Protocol) or Async to Sync SLIP (Serial Line
Internet Protocol) protocol.

Making Async to Sync PPP and SLIP calls

In order to communicate with an ISDN LAN router (from vendors such as Ascend and
Cisco), you'll need to set the Omni TA128 B channel protocol to one of the following:
ATB40<Enter> (HDLC PPP)
or
ATB41<Enter>(HDLC SLIP)
You should also set the DTE speed based on the bandwidth that the switches support.
Most of the time, you will only use this protocol for making calls to remote sites with
ISDN LAN Routers. If the remote access site you are calling uses a Terminal Adapter
such as the Omni TA128, you can use V.120 (see next chapter), as it provides data
compression.
Before making the call, check which protocol is set for the ISDN mode using the &V
command to view the settings.
Type:
AT&V<Enter>
The Omni TA128 responds:
Current Settings...
Switch Type: Northern Telecom DMS
ISDN Outgoing Service: PPP Async-to-Sync Conv 64K
If the settings displayed match your current setup, you are ready to place the call.
Type:
ATDI<remote_access_number><Enter>
Omni TA128 will respond:
Connect 115000/64000 PPP/None
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