Professional Network Management Company
Xelas Software provides components for TMN based management, convergent multiprotocol mediation, OSS integration, network management and electronic bonding solutions.

Xelas Software X.400 and X.500 products

The Xelas Software X.400 Message Handling System suite of products implements a comprehensive messaging solution, based on the ITU series of standards for electronic messaging, governing the submission, transfer, delivery and retrieval of messages.

X.400 messages come in to the Message Transfer System (MTS) via user agents or access units. The MTS consists of a number of Message Transfer Agents (MTAs), each of which is responsible for the routing of messages to remote MTAs, or alternatively, delivery to the local X.400 system. MTAs may be grouped into public domains (Administration Management Domain, or ADMD), or private domians (Private Management Domain or PRMD.)

The MTA functionality in the MTS above is implemented in three modules:

  • P1 Message Transfer Agent (P1 MTA)
    This is responsible for the routing and transfer of messages between adjacent MTAs, based on information provided by the P1 protocol. If a message is for the local domain, the P1MTA delivers it.
  • P3 Message Transfer Agent (P3 MTA)
    This module has a delivery and submission role, for users without a message store, based on the P3 protocol.
  • P1 Association Manager (P1 AM)
    This is the P1 communications manager in the X.400 system. It controls the communications between adjacent P1MTA modules.

The Xelas Software MHS also implements the following modules:

  • Message Store (MS)
    This module provides for the storage and access of messages on behalf of users. It effectively implements the mailbox in an X.400 system. An MS also allows submission of new messages.
  • P3/P7 Association Manager (P3P7 AM)
    This is the communications manager for remote communications between User Agents and the Message Store (according to the P7 protocol), and between User Agents and the P3MTA (according to the P3 protocol).
  • Example P7 User Agent
    A P7UA is an application process that interacts with an MS for message submission and retrieval (as well as control operations). Such a UA could be a GUI facing a real user, or it could be an automatic process. Typically, since this is the user-facing part of the X.400 MHS, each company will want to have their own front-end. This module presents a fully-functional example UA.
  • Reliable Transfer Service (RTS)
    This module is the means by which the reliable transfer of Application Protocol Data Units (APDUs) is implemented. This ensures the integrity of transfers to/from MTAs, Message Stores, and User Agents. The functionality of the RTS is incorporated into the P1AM and P3P7AM modules above.
  • The P1MTA and MS above can also optionally support Electronic Data Interchange (EDI.)

The Xelas Software MHS has been ported to a variety of systems including Redhat Linux, Sun Solaris, and HPUX. It can also be configured to run over TCP, LAN and WAN stacks.

Xelas Software maintains and sells the Retix/Vertel X.400 and X.500 products.
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