🚀 go-pugleaf

Hi,

I recently started to take a closer look at the interfaces between the
ISO layers. In particular, I looked at ISO DIS 10022, which describes
the interface between the physical layer (Layer 1) and the data link
layer (Layer 2).

ISO DIS 10022 describes three "Physical Service primitives":
	- Ph-ACTIVATE request/indication
	- Ph-DATA request/indication
	- Ph-DEACTIVATE request/indication.

I have a question concerning connection establishment, i.e. a Ph-ACTIVATE
request:

ISO DIS 10022 sais that with a Ph-ACTIVATE request, "Parameters
associated with the class of service are for further study",
but refers only to such things as
	- Type of transmission (synchronous and asynchronous),
	- Mode of operation (duplex, half-duplex, and simplex), and
	- Topology (point-to-point and multi-endpoint).

If I have a dial-up line, e.g. a V.24 (RS232) connection with a V25bis
modem or an X.21 connection, the connection establishment phase in each
of these two configurations is somewhat different to the data transfer
phase, how would one specify things like
	- type of transmission while dialling (in V.25bis one could dial
	  synchronous and then transfer asynchronous)
	- what "number" to dial?

PLEASE no answers like "You would never use this interface explicitly"!

Thanks,

--
| Josef Moellers		|	c/o Nixdorf Computer AG	|
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