Conformance for the M-Switch ACP127 and M-Switch Encryption add-ons as well as for the M-Switch Constrained Network Server and Gateway, which are additional to the Open Standards listed below, can be found on the product pages for those products and add-ons.

The base X.400 standards and ISPs (International Standard Profiles) are set by two bodies.

  • The ITU (International Telecommunications Union) as a series of documents collectively referred to as X.400. There are a number of documents in this series (e.g., X.400, X.402, X.420).
  • ISO (International Organization for Standardization) and IEC (International Electrotechnical Commission) as MOTIS (Message Oriented Text Interchange Systems) and the ISO/IEC 10021 series. These documents are equivalent (e.g., ISO/IEC 10021-7 is equivalent to X.420).

The ITU and ISO documents are technically aligned. There are some small differences because the ITU documents relate only to interconnection with public services, whereas the ISO/IEC documents also cover "local" issues. Isode supports these differences, which relate to different deployment situations, and do not affect interoperability. Conformance to X.400 base standards is listed below.

ITU X.400 Message Handling System: System and Service Overview. ISO/IEC 10021-1, 1999
ITU X.401 Naming and addressing for public message handling services. 1992
ITU X.402 Message Handling Systems (MHS): Overall Structure. ISO/IEC 10021-2, 1999
ITU X.411 Message Handling Systems (MHS): Message Transfer System: Abstract Service Definition and Procedures. ISO/IEC 10021-4, 1999
ITU X.419 Message Handling Systems (MHS): Protocol Specifications. ISO/IEC 10021-6, 1999
ITU X.420 Message Handling Systems (MHS): Interpersonal Messaging System. ISO/IEC 10021-7, 1996

In order to deal with specification of an X.400 system, there are a series of ISPs (International Standard Profiles) published in conjunction with the base X.400 specifications. "ISO/IEC 10611-1: Common Messaging Part 1: MHS Service Support (1999)" sets out a core framework for the X.400 ISPs. In particular it defines a set of functional groups, to which an implementation can claim conformance. The following table lists all of the X.400 functional groups, and which ones are supported by M-Switch X.400.

Functional Group M-Switch X.400 Support Notes
Conversion (CV) Supported  
Distribution List (DL) Supported  
Physical Delivery (PD) Not Supported All elements supported required of an MTA that is co-resident with a Physical Delivery Access Unit.
Redirection (RED) Supported  
Latest Delivery (LD) Supported  
Return of Contents (RoC) Supported  
Security (SEC) Supported to the S0 Level S1 level is supported for P1, but not for P3.
Use of Directory (DIR) Supported  
1984 Interworking (84IW) Supported, excluding internal trace information  
Simple Protected Password (SPP) Not Supported Strong Authentication is preferable.
Redirection Instructions (RED2) Not Supported Only relevant to MTS84 (AMH14), and not core MTA function.
Delivery Constraints (DC) Not Supported Only relevant to MTS84 (AMH14), and not core MTA function.
Restricted Delivery (RD) Not Supported Only relevant to MTS84 (AMH14), and not core MTA function.

Message Transfer & Access Conformance

An MTA must support Message Transfer, using the X.400 P1 protocol. M-Switch is conformant to the core ISP requirements for the 1984, 1988, and 1996, 1999 and 2003 versions of X.400. Detailed specification of the Message Transfer Conformance of M-Switch X.400 is provided in two PICS statements:

Message Access refers to submission and delivery using the X.400 P3 protocol. There are two versions of the X.400 P3 protocol:

  • P3 (1988), with conformance defined in AMH12 (MTS Access) and AMH 23 (IPM Requirements for MTS Access).
  • P3 (1994), with conformance defined in AMH14 (MTS94 Access) and AMH 25 (IPM Requirements for MTS94 Access). This defines additional end user management and control functions.

Extensions from X.400(1994) and X.400(1999) can be used with both of these protocols. Isode supports P3(1988) only. Details of M-Switch X.400 P3 conformance is defined in "AMH12 and AMH14 - MTS Access (P3) and MTS 94 Access (P3)" ISO/IEC ISP 10611-4. This is aligned to ITU X.483 "P3 PICS". Isode is conformant to the mandatory elements of the ISP for P3(1988), with two exceptions:

  • DeliveryControl operation is not supported. M-Switch X.400 achieves the functions of this operation by use of its own configuration management tools. This allows access to controls by P7 users and administrators, which increases flexibility.
  • For the MTS Forced Access protocol, M-Switch X.400 supports only delivery (and not submission). This reflects use of MTS Forced Access to deliver messages from M-Switch to a Message Store, where submission is not needed. P3 Clients can submit and deliver messages using MTS Access.

Lower Layers: X.400 & RTSE

The X.400 channels support the 1984, 1988 and 1992 recommendations including the mts-transfer (P1-1988, RTSE normal-mode), mts-transfer-protocol (P1-1988, RTSE X.410(1984)-mode) and mts-transfer-protocol-1984 (P1-1984, RTSE X.410(1984)-mode) application contexts.

Full RTSE recovery is supported for both inbound and outbound transfers. There is full support for Two Way Alternate. All three application contexts can be supported by a receiving channel on a single Session address.

Military Standards

STANAG 4406 Edition 2: Annex A Military Message Handling System, Annex A: MMHS Extensions, March 2005
STANAG 4406 Edition 2: Annex B Military Message Handling System, Annex B: Interoperability of Secure MMHS, March 2005
STANAG 4406 Edition 2: Annex C Military Message Handling System, Annex C: Alpha Profiles Set, March 2005
STANAG 4406 Edition 2: Annex G Military Message Handling System, Annex G: Compatibility with PCT based MMHS Security, March 2005
STANAG 4406 Edition 2: Annex H Military Message Handling System, Annex H: NATO Security Labelling Guidence for MMHS, March 2005

In addition to the above M-Switch X.400 supports ACP142 (Version 1.0) "P_MUL - A Protocol for Reliable Multicast Messaging in Bandwidth Constrained and Delayed Acknowledgement (EMCON) Environments" for use with Data Diodes only. ACP142 for use in constrained cetwork environments is supported in the M-Switch Constrained Network products.

Other Conformance

RFC 1328 X.400 1988 to 1984 downgrading, S. Kille, May 1992
SARPS ICAO SARPS Doc 9880-AN/466 - Manual on detailed technical specifications for the Aeronautical Telecommunication Network using ISO/OSI standards and protocols, Part IV – Directory Services, Security and Systems Management. Second Edition.