MSAG (Master Street Address Guide)

A database of street names and house number ranges within their associated communities defining Emergency Service Zones (ESZs) and their associated Emergency Service Numbers (ESNs) to enable proper routing of 9-1-1 calls.

MSAG Address
Address recognized by Public Safety for the dispatch of emergency first responders. It is an absolute and unique address in that variants for directions, street spelling, street suffixes, and community names are not allowed. It is preferred that MSAG Addresses be in Civic Address format. The community name associated with this address format is assigned by the Addressing Authority in cooperation with the 9-1-1 Administrator and may or may not be the same as the community name assigned by the USPS. MSAG addresses are used to route 9-1-1 calls and for ALI display. NOTE: MSAG Address data format is not standardized throughout the country. This is generally attributed to legacy system limitations that have been continued as operational practices on the part of 9-1-1 administrative entities. This fact gives rise to the need for two subtending MSAG definitions. (See Standard MSAG and Local Operational MSAG.)

Baseline MSAG
MSAG file that is a snapshot image which represents a complete, up-to-date set of MSAG data at the point in time it was created.

Civic to MSAG Translation
Translations consist of processes, tables or rules that can be used to: Translate a Civic Address from/to an MSAG-format address. Translate a Postal Address from/to an MSAG-format address. Translate Landmark from/to an MSAG-format address (e.g. Empire State Building ---' 350 5TH AVE). A civic address may need to be translated so that the data is consistent to the format within the existing PSAP equipment and processes (i.e., CAD, mapping, CPE).

Definitive Civic Address
In the context of location information to support IP based emergency services: An address that can be resolved into a local MSAG valid address, will yield a route to the correct PSAP when used to route an emergency call, and is bound to a specific VoIP end-point.

Delta MSAG
The Delta MSAG is a file of incremental changes to the MSAG. The changes are applied in the order that they are presented, to either the last updated version of the MSAG or a current Baseline of the MSAG, whichever is more recent.

MSAG Administrator
Identifies appropriate organizational entities that have an accepted need for the MSAG in order to support E9-1-1 (e.g., DBMSPS, SPs, Wireless, VDBs, ERDBs, VSPs).

MSAG Operator
Typically the Database Management System Provider (DBMSP). Works in conjunction with 9-1-1 Administrator to provide and maintain the database equipment and infrastructure that supports the access and retrieval of the MSAG data by authorized parties.

MSAG Consumer
Identifies appropriate organizational entities that have an accepted need for the MSAG in order to support E9-1-1 (e.g., DBMSPS, SPs, Wireless, VDBs, ERDBs, VSPs).

MSAG Discrepancy
An MSAG Discrepancy is defined as a record being retrieved from ALI during an actual E9-1-1 call with incorrect information because an MSAG field was incorrect. For example, incorrect ESN assignment or transposition of numbers, incorrect house number ranges, odd/even indicator.

MSAG Error
An MSAG error is defined as a hard error from DBMS service order processing or a manual update that failed to meet the MSAG specifications.

MSAG Source
Represents a recognized supplier of MSAG files, which may be the MSAG Administrator, or an authorized MSAG Operator. The MSAG Source is typically the E9-1-1 System Service Provider, but may be the 9-1-1 Administrator's MSAG Administrator.

MCS
MSAG Conversion Services