RFC 2303 and 2304:
Interworking Configuration Matrix

Feature Set

Requirement Level

Condition

Support
(Y, N, N/A)

Interworking
Tested

RFC 2303 - Section 1: Introduction

Minimum RFC 2303 Specification (1.)

MUST

1. All implementations supporting this PSTN over e-mail service MUST support as a minimum the specification described in (RFC 2303).

RFC 2303 - Section 2: Minimal PSTN Address

Non-Minimal Extensions (2.)

MAY

2. Implementations confirming to the minimal requirements specification are allowed to ignore any other non-minimal extension address elements which are present in the "pstn-address".

MUST

3. Conforming implementations MUST preserve all "qualif-type1" address elements they receive.

Global Phone Syntax (2.1 - both RFCs)

MUST NOT

4. Any non "global-phone" dialling schema MUST NOT use the leading "+" between the "=" sign and the dialling string. The "+" sign is strictly reserved for the standard "global-phone" syntax.

Written SEP Elements (2.1 - both RFCs)

MAY

5. Use of the written-sep elements is allowed, but not recommended.

MUST

6. Any occurrences of written-sep elements in a pstn-mbox MUST be ignored by all conformant implementations.

SHOULD

7. User Agents SHOULD remove written-sep elements before submitting messages to the Message Transport System.

RFC 2303- Section 3: The e-mail address of the I-pstn device: mta-I-pstn

Domain String (3. - both RFCs)

MUST

8. For "domain" strings used in SMTP transmissions, the string MUST conform to the requirements of that standard's <domain> specifications (RFC 821/RFC 1123).

MUST

9. For "domain" strings used in message content headers, the string MUST conform to the requirements of the relevant standards (RFC 822, RFC 1123).

RFC 2303, Section 4: The pstn e-mail

pstn-email element (4.- both RFCs)

MUST

10. Implementations MUST accept the optional slashes "/" (in the pstn-email element).

SHOULD NOT

11. Implementations SHOULD NOT generate (slashes "/").

MAY

12. Gateways are allowed to strip them off when converting to Internet mail addressing.

MUST

13. The ""pstn-address" element MUST strictly follow the "quoting rules" specified in the relevant standards (RFC 822, RFC 1123).

Multiple Subaddresses (RFC 2303 - 4.1)

MUST (WILL)

14. For services that require multiple subaddresses, for the same "pstn-mbox", multiple "pstn-email" elements will be used.

MUST

15. The UA could accept multiple subaddress elements for the same global-phone, but it must generate multiple "pstn-mbox" elements when passing the message to the MTA.

RFC 2303/2304 - Section 6: Security Considerations

Mail Routing (6. - both RFCs)

SHOULD

16. Clients SHOULD ensure that mail routing (as a result of Domain Name information) is based only on authoritative answers.

SHOULD

17. Once DNS Security mechanisms [RFC 2065] become more widely deployed, clients SHOULD employ those mechanisms to verify the authenticity and integrity of mail routing records.

RFC 2304 - Section 1: Introduction

Minimum Specification (1.)

MUST

18. All implementations supporting this FAX over e-mail address format MUST support as a minimum the specification described in this document (RFC 2304).

RFC 2304 - Section 2: Minimal Fax Address

qualif-type1 element (2.)

REQUIRED

19. The minimal addressing for the fax service also requires support for a "qualif-type1" element. This element is an OPTIONAL element of the fax address, but its support, when present, is REQUIRED:
qualif-type1 = "/" t33-sep "=" sub-addr

Fax address minimum specification (2.1)

REQUIRED

20. The minimal specification of a fax in e-mail address is:
fax-address = fax-mbox [ "/T33S=" sub-addr ]
fax-mbox = "FAX=" global-phone

RFC 2304 - Section 2: Minimal Fax Address

Multiple T.33 Subaddresses (4.1)

MUST

21. In case a particular service requires multiple T.33 subaddresses, and these subaddresses need to be given on the same "fax-mbox", multiple "fax-email" elements will be used.

MUST

22. In case a particular service requires multiple T.33 subaddresses, and these subaddresses need to be given on the same "fax-mbox", multiple "fax-email" elements will be used.