• United States
by Steve Taylor and Larry Hettick

Building blocks to unified messaging

Mar 24, 20042 mins

* The roles of SMTP, POP, IMAP, VPIM and LDAP in unified messaging

As mentioned in the previous issue, the road to unified messaging contains several key building blocks and vendor support for these will affect a company’s effectiveness at deploying unified messaging. 

The building blocks include:

* SMTP. Simple Mail Transfer Pprotocol was introduced by the IETF back in 1982 and provides users with a common protocol for sending e-mail messages between different suppliers’ e-mail systems.  SMTP clients will identify an intermediate destination through which all mail messages are to be relayed. Because e-mail message delivery is a component of unified messaging, SMTP support is a requirement for unified messaging systems.

* POP and IMAP. Once e-mail messages are sent to an SMTP server, they can be retrieved using either Post Office Protocol (POP) or Internet Message Access Protocol (IMAP). Although POP (as the earliest retrieval protocol) has been more widely deployed than IMAP, IMAP provides some key advantages. IMAP permits an e-mail program to access remote message stores as if they were local. This access technique lets a user manipulate the e-mail from a computer without the need to transfer messages or files back and forth. IMAP also can be used for access to non-e-mail data.

* VPIM. Similar to how SMTP, POP, and IMAP are protocols for e-mail, the IETF’s Voice Profile for Internet Mail (VPIM) is a standard intended for sending voice messages between voice messaging systems. VPIM supports voicemail, faxes, paging and text-based messages. With VPIM, users of traditional voicemail systems can continue to access and operate their systems via the telephone, while users of the unified messaging systems can use graphical PC screens and mouse clicks. VPIM simply lets these systems exchange messages across TCP/IP-based intranets and the Internet.

* LDAP.  Lightweight Directory Access Protocol is both an information model and a set of IETF protocols designed for querying and manipulating data. LDAP is designed to run directly over the TCP/IP stack. It is based on the standards contained within the X.500 standard, but is significantly simpler. LDAP makes it possible for computer-based applications to obtain directory information such as names, e-mail addresses, and phone numbers.

While specific protocol support is important, unified messaging systems also need to support some other basics.  We’ll cover those next time.