Microsoft Exchange 2000 Operation Manual page 113

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Glossary
Messaging service in Exchange 2000 uses a Microsoft published protocol called Rendezvous
Protocol (RVP) while IMPP is being ratified
Internet Messaging Access Protocol version 4 – IMAP4
A standard-based protocol for accessing mailbox information. IMAP4 is considered
to be more advanced than POP3 because it supports basic online capabilities and access to
folders other than the Inbox. Exchange Server 5.x and Exchange 2000 both support
IMAP4.
Joint Engine Technology – JET
Defines the low-level access to underlying database structures in Exchange Server 4.0 and
5.0. JET was superceded with the Extensible Storage Engine (ESE) in Exchange Server 5.5
and Exchange 2000.
Lightweight Directory Access Protocol – LDAP
A standards-based protocol that can be used to interact with conformant directory ser-
vices. LDAP version 2.0 allows for reading the contents of a directory database, whereas
LDAP version 3.0 (defined under RFC2251) allows users and applications to both read
and write to a directory database. LDAP was developed by Tim Howes and the University
of Michigan.
Link State Algorithm – LSA
The algorithm used to propagate routing status information between servers running
Exchange 2000. Based on 'Dijkstra's algorithm', link state information is transferred
between routing groups using the X-LINK2STATE command verb over Simple Mail
Transfer Protocol (SMTP)SMTP and within a routing group using a Transmission Control
Protocol (TCP) connection to port 691.
Mail-based replication – MBR
A mechanism to replicate directory information through a messaging transport. This term
applies to Exchange 5.x inter-site directory replication, and additionally, Active Directory
replication through SMTP.
MD (Message Digest Algorithm, MD4, MD5)
Developed by Rivest, this takes a message of arbitrary length and produces a 128-bit
message digest. The algorithm is optimized for 32-bit machines. Description and source
code for MD4 and MD5 can be found as Internet RFCs 1319 – 1321.
MDB
An instance of a database implemented in Exchange server. A single MDB is normally
identified as being public or private depending on the type of data that it stores. A single
server running Exchange 2000 can accommodate up to 20 active MDBs.
Message Transfer Agent – MTA
The component in all versions of Exchange Server that transfers messages between servers
using the X.400 protocol.