josef@nixdorf.de (Moellers) (10/29/90)
Hi,
I've tried to post this before, but either the message didn't make ist
out or nobody answered B-{(
ISO/IEC DIS 10022 describes the "Physical service definition", i.e. the
interface between Layer 1 and Layer 2.
It describes the interface in terms of primitives:
- Activation
- Data Transfer
- Deactivation
One of the activation primitives (Ph-ACTIVATE request) is used to
establish a connection between two PhC endpoints.
When one uses a modem with dialing protocol V.25bis or an X.25
connection, the connection establishment phase uses a different
configuration on the "control lines" while dialing.
Questions:
1. Is this dialing part of ISO layer 1 (physical layer)?
In my opinion, it is.
2. How do I specify the address/numbers to use?
DIS 10022 only says that parameters to the activation primitives
concern the classes of service, but no mentioning of any dialing
parameters.
--
| Josef Moellers | c/o Siemens Nixdorf Informatonssysteme AG |
| USA: mollers.pad@nixdorf.com | Abt. PXD-S14 |
| !USA: mollers.pad@nixdorf.de | Heinz-Nixdorf-Ring |
| Phone: (+49) 5251 104662 | D-4790 Paderborn |enag@ifi.uio.no (Erik Naggum) (11/01/90)
In article <josef.657189877@peun11> josef@nixdorf.de (Moellers) writes:
Questions:
1. Is this dialing part of ISO layer 1 (physical layer)?
In my opinion, it is.
In my opinion, it's part of a primitive Network Layer.
2. How do I specify the address/numbers to use?
Have you tried a sequence of digits? :-)
Seriously, being part of the Network Layer, I would guess you could
construct some Network Service Access Point address which would
conveniently map to the telephone number.
Note: By putting connection establishment into the Network Layer, you
can use different Data Link protocols for connection establishment and
release than for data transfer, since you talk to the modem.
I'm almost of the opinion that you could construct a whole seven-layer
model for dialling and phone protocols. They did it with Digital
Subscriber Signalling system # 1 and Signalling System # 7, yet I
routinely view the dialling and the phone connection as pretty
low-level.
Moral: The ISO RM for OSI applies from several angles of view.
--
[Erik Naggum] Naggum Software; Gaustadalleen 21; 0371 OSLO; NORWAY
I disclaim, <erik@naggum.uu.no>, <enag@ifi.uio.no>
therefore I post. +47-295-8622, +47-256-7822, (fax) +47-260-4427
--josef@nixdorf.de (Moellers) (11/05/90)
In <ENAG.90Nov1075351@hild.ifi.uio.no> enag@ifi.uio.no (Erik Naggum) writes: >In article <josef.657189877@peun11> josef@nixdorf.de (Moellers) writes: > Questions: > 1. Is this dialing part of ISO layer 1 (physical layer)? > In my opinion, it is. >In my opinion, it's part of a primitive Network Layer. I know that connection establishment is part of the Network Layer, but ... My main problem is with the signals on the control lines, like CTS, RTS, DSR, DTR, RI, ...). If you look at said (draft) standard ISO/DIS 10022 it only specifies a PhC-ACTIVATE request with "Parameters associated with the classes of service (see clause 8) are for further study", and "Clause 8" mentioning a) Type of transmission: synchronous and asynchronous b) Mode of operation: duplex, half-duplex, and simplex. [ Stuff left out here ] c) Topology: point-to-point and multi-endpoint. To get back to my examples: V.25bis or X.25: During connection establishment, both have states of the control lines that are distinct from the state of the control lines during data transfer. E.g. V.25 bis specifies that during the dialling phase (V.25bis calls this "DTE-DCE dialogue" and "Call establishment") DTR=ON DSR=OFF RTS=ON RI=OFF Whereas during data transfer DTR=ON DSR=ON <<<! RTS=X RI=OFF > 2. How do I specify the address/numbers to use? >Have you tried a sequence of digits? :-) >Seriously, being part of the Network Layer, I would guess you could >construct some Network Service Access Point address which would >conveniently map to the telephone number. >Note: By putting connection establishment into the Network Layer, you >can use different Data Link protocols for connection establishment and >release than for data transfer, since you talk to the modem. >I'm almost of the opinion that you could construct a whole seven-layer >model for dialling and phone protocols. They did it with Digital >Subscriber Signalling system # 1 and Signalling System # 7, yet I >routinely view the dialling and the phone connection as pretty >low-level. My question stays as it is: ISO/DIS 10022 specifies that in order to activate a PhC (Physical Connection), one has to send a PhC-ACTIVATE request to the Layer-1 Module. From the DIS, I would depict this as (example): <PhC-ACTIVATE, asynchronous, duplex, point-to-point> But this doesn't specify what "number to dial". My idea would be something like (example): <PhC-ACTIVATE, asyncronous, duplex, point-to-point, ":0049=1234=56789;9999"> for a V.25bis Modem. If I am wasting bandwidth on this rather trivial matter, sorry! -- | Josef Moellers | c/o Siemens Nixdorf Informatonssysteme AG | | USA: mollers.pad@nixdorf.com | Abt. PXD-S14 | | !USA: mollers.pad@nixdorf.de | Heinz-Nixdorf-Ring | | Phone: (+49) 5251 104662 | D-4790 Paderborn |