Maintenance Operations Protocol

The Maintenance Operation Protocol (usually abbreviated as "MOP") originated about 1976 as a part of the DECnet Phase II network protocol suite. It provides network services for management and maintenance.

Naming Conventions

• A "host" is a computer that provides MOP services
• A "satellite" is a computer or network device that uses MOP services.

Functions

MOP provides several functions:

• Down-Line loading (host to satellite) of memory contents, e.g. for booting diskless computers and network devices such as terminal servers
• Up-Line loading (satellite to host) of memory contents, e.g. for failure analysis
• Testing of network hardware and cabling
• Force satellite entry into the MOP mode, i.e. halt current satellite operation and put the satellite into MOP mode. This provides a means for the host to control an unattended satellite system.
• Remote Console

MOP works on the local network link only.

Configuration

MOP is configured via the DECnet Network Control Program, (usually abbreviated as "NCP"). All configuration takes place on the host computer only.

Most NCP commands used for MOP configuration are identical for all versions of all DEC operating systems. The following examples are for DECnet VMS V4.0 and newer.

Activate MOP service on circuit UNA-0 (= Ethernet device DEUNA or DELUA; replace with your network device type DECnet circuit-id):

$ MC NCP SET CIRCUIT UNA-O STATE OFF
$ MC NCP DEF CIRCUIT UNA-O SERVICE ENABLED 
$ MC NCP SET CIRCUIT UNA-O SERVICE ENABLED STATE ON 

This enables the host computer to answer any incoming MOP requests on network circuit UNA-0.

If the MOP request is a satellite download request (e.g. for booting), some parameters have to configured first, e.g.:

• Satellite DECnet address
• Satellite node name
• Load file
• ... and possibly others depending on the task to perform.

For details see the respective manuals.

Debugging

For debugging purposes it is helpful to enable MOP related event logging (Examples for VMS V4.0 and later):

Enable OPCOM messages to the current terminal:

$ Reply/Enable

Enable DECnet logging to the OPCOM process:

$ MC NCP SET LOGGING CONSOLE STATE ON

Activate DECnet event 0.3 "Automatic circuit service":

$ MC NCP SET LOGGING CONSOLE EVENT 0.3

Activate DECnet event 0.7 "Aborted service request":

$ MC NCP SET LOGGING CONSOLE EVENT 0.7

History

MOP underwent continuous development; the last known revision is 4.0.0, dating from 1992. With the introduction of VMS V6.2 in 1995, MOP was decoupled from DECnet and integrated into the OpenVMS distribution with the new LANCP (LAN Control Program) command interface.

MOP Revision History

Revision	Date	Reference
1.1	January 1976	cited at: AA-D602A-TC Maintenance Operation Protocol, pdf page 37
2.0	March 1978	AA-D602A-TC Maintenance Operation Protocol
2.1.0	October 1980	AA-K178A-TK DECnet Digital Network Architecture Phase III Maintenance Operation Protocol
3.0.0	December 1983	AA-X436A-TK DECnet Digital Network Architecture Phase IV Maintenance Operations Functional Specification
4.0.0	June 1992	EK-DNA11-FS-001 Maintenance Operation Protocol Functional Specification Version 4.0.0

See also

DECnet