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Autocall del ay, Called address, Retr y count – Cabletron Systems 1800 User Manual

Page 190: Retr y interval, User data, Faci lities, Dtr/rts active when vc up, Input signal detection, Rts-cts h/w flow control

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12-12

SmartSwitch 1800 4. 0 User G uide, Rev 01

Autocall Delay

causes a delay after the link comes up before a Call Request will be issued.

Called Address

is the ID of the remote device, and is placed into the called address field of the Call
Request. This parameter is relevant only if

Autocall

is

Y

; if

Autocall

is

N

, the called

address will come from either the user device’s X.28 interface or an abbreviated
address.

If the async port is one end of a connection to a logical X.25 port in the SmartSwtch,
the Called Address must match a

Subscriber ID

(see page 12-15) configured for the

logical port.

Retry Count

is the number of times an autocall will be sent to the remote device.

Retry Interval

is the time between autocall attempts.

User Data

is an (optional) string of ASCII characters that will be placed verbatim into the user
data field of an outgoing Call Request packet.

Facilities

is an (optional) string of facility codes and related data that will be placed verbatim
into the facility field of an outgoing Call Request packet.

DTR/RTS Active When VC Up

if

Y

means that DTR and RTS will be asserted only after a virtual circuit is established.

If

N

, both signals will be asserted as soon as the port is enabled.

Input Signal Detection

determines which signal(s) will be read to determine that the link is up:

0

= none required

1

= DSR

2

= DSR & DCD

3

= DSR & DCD & Call

4

= DSR & CTS

5

= DSR, DCD, & CTS

RTS-CTS H/W Flow Control

enables hardware flow control through stop/start of data using RTS (pin 4), CTS (pin
5), and CD (pin 8) on the RS-232 interface. Flow control is usually necessary to
maintain communication without data loss between devices or channels with different
throughput capabilities.

RTS-CTS flow control works only on a physical DTE port, as physical DCE ports
have RTS looped back internally to CTS.

The other common method of flow control is XON-XOFF (parameters 5 and 12 of the

async PAD profile

); however, when the data itself is likely to contain these characters

(for example, in a binary file), XON-XOFF may become inadequate.