AT&T DS1/DMi/ISDN-PRI manual Field

	ADMINISTRATION OPTIONS AND REQUIREMENTS — SYSTEM 85	7-17
Field 5	V4 Only
	Assigns the interface type or side. The default option is (0) for user side.
	Alternately, a (1) should be administered for network side. The configuration of
	the network should be analyzed to determine if the (0) option is appropriate.
	For MOS-type facilities (such as DMI-MOS and ISDN-PRI), each link must be
	segmented into user and network sides. Each System 85 R2V4 MOS-based
	transmission facility connecting to the public network will always be the user side
	(0), while the network side (for example, a 5ESS or 4ESS) is administered (1). For
	private network DMI-MOS and ISDN-PRI connections, additional care must be
	exercised in defining user and network sides. Specifically, only one end must be
	administered user side (0), while the alternate must be defined as the network side
	(1). If the private network node is a tandem switch, then that node may function as
	both user side and network side depending on the particular facility.
	NOTE: For System 85 R2V4 DMI-MOS to host computers equipped with
	MOS, the computer should always be assigned as the network side.
Field 6	V4 Only

Administers the facility test code. For most installations it is desirable to enable or establish permission, thus allowing selected maintenance software to test the DMI- MOS/ISDN-PRI transmission facility on a demand basis.

Procedure 648 contains several tests that may be done on a demand basis (by executing procedure 648) when facility test code 1, 2, or 3 is administered).

The DMI-MOS/ISDN-PRI communication protocol consists of three layers or levels. Level 1 is the physical layer. Level 2 is the data link layer. Level 3 is the network layer, also called the link access procedure on the D-channel(LAPD).

Field encodes and their descriptions are:

0 Disables or prohibits maintenance testing from being done on the specified (module, cabinet, carrier, and slot) transmission facility.

1 Selects level-2 testing via procedure 648.

NOTE: This encode should be translated for all DMI-MOS to host computer links.

2Selects level-3 (network layer) testing. Level 3 does loopback testing and requires the use of a separate special test line (SN261C Analog Digital Facility Test Circuit).

3Permits both level-2 and level-3 tests to be done.

NOTE: This encode should be translated for all ISDN-PRI connections that terminate on a 4ESS.