HP-UX SNAplus2 R7 Administration Guide

Deﬁning Connectivity Components

Deﬁning DLCs, Ports, and Connection Networks

Select a value that describes the role of the local node for link stations deﬁned on this port. In SDLC

communication, one end manages the link and is called the primary link station. The other end is the

secondary link station.

Use one of the following values for this ﬁeld:

Secondary

The other end of the link is to be the controller and the remote system is conﬁgured to be primary.

This is nearly always the case if you are conﬁguring a link to a host system.

Primary

This port is to act as the SDLC controller of the link, and the remote system is conﬁgured to be

secondary.

Negotiable

For maximum ﬂexibility, this setting enables the two ends to negotiate which end performs the

primary role. Choose this value if you do not know which role is conﬁgured for the remote

system.

You can use this setting for a peer link, but be aware that negotiating the role causes a short delay

when the link is activated.

Primary Multi-drop

The link is leased and this port is to act as controller of a multi-drop link to several secondary

nodes.

Use this setting when you want to conﬁgure several link stations from the local node to different

remote nodes (for example, for links to downstream nodes). Each of these other nodes must be

conﬁgured as secondary, and you must be using a leased line.

Secondary Multi-PU

The local port is one of the secondary stations on a multi-drop link controlled by the port on the

remote system.

If you conﬁgure a port for a switched incoming or leased line, you also need to conﬁgure the following items:

Encoding

Select NRZ or NRZI for the encoding used on your SDLC line.

This value must match the encoding scheme used by the modem at the remote end of the link. If you

set this ﬁeld incorrectly, you will ﬁnd that the frames being received are all discarded and do not appear

in any trace.

On a VTAM host, this is the

NRZI= setting in the LINE/GROUP deﬁnition.

Duplex Setting

Select Half Duplex or Full Duplex, depending on the capabilities of your SDLC cable and

modems. If the modems at both ends are capable, choose Full Duplex for higher throughput.

For switched outgoing ports, you conﬁgure the line encoding and duplex settings on each link station (see

Section 5.2, Deﬁning Link Stations) instead of on the port.

If you conﬁgure a switched incoming port, you need to conﬁgure the following:

Dial string

An ASCII string to be sent to your modem in order to prepare it to accept incoming calls.

By default, the dial string is sent to the modem at the rate of 1200 bits per second (the default baud

rate) using asynchronous communications. You can match the baud rate to the modem’s baud rate by

placing one of the following numbers, enclosed by parentheses, in front of the dial string: