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- Network Working Group M. Rose
- Request for Comments: 1703 Dover Beach Consulting, Inc.
- Obsoletes: 1569 October 1994
- Category: Informational
-
-
- Principles of Operation for the TPC.INT Subdomain:
- Radio Paging -- Technical Procedures
-
- Status of this Memo
-
- This memo provides information for the Internet community. This memo
- does not specify an Internet standard of any kind. Distribution of
- this memo is unlimited.
-
- Table of Contents
-
- 1. Introduction ............................................... 1
- 2. Naming, Addressing, and Routing ............................ 2
- 2.1 Addressing ................................................ 2
- 2.2 Routing ................................................... 3
- 3. Procedure .................................................. 3
- 3.1 Alpha-numeric Radio Pagers ................................ 3
- 3.2 Numeric Radio Pagers ...................................... 4
- 3.3 MAILing versus SENDing .................................... 4
- 3.4 Latency ................................................... 5
- 4. Usage Examples ............................................. 5
- 4.1 A MIME Example ............................................ 6
- 4.2 A Non-MIME Example ........................................ 6
- 5. Server Configuration Example ............................... 6
- 6. Security Considerations .................................... 8
- 7. Acknowledgements ........................................... 8
- 8. References ................................................. 8
- 9. Author's Address ........................................... 9
-
- 1. Introduction
-
- As an adjunct to the usual, two-way electronic mail service, it is at
- times useful to employ a one-way text notification service, called
- radio paging. This memo describes a technique for radio paging using
- the Internet mail infrastructure. In particular, this memo focuses
- on the case in which radio pagers are identified via the
- international telephone network.
-
- The technique described by this memo, mapping telephone numbers to
- domain names, is derived from the TPC.INT subdomain. Consult RFC
- 1530, "Principles of Operation for the TPC.INT Subdomain: General
- Principles and Policy" for overview information.
-
-
-
- Rose [Page 1]
-
- RFC 1703 Radio Paging -- Technical Procedures October 1994
-
-
- 2. Naming, Addressing, and Routing
-
- A radio pager is identified by a telephone number, e.g.,
-
- +1 415 940 8776
-
- where "+1" indicates the IDDD country code, and the remaining string
- is a telephone number within that country.
-
- In addition to a telephone number, a PIN may also be required to
- uniquely identify a radio pager.
-
- 2.1. Addressing
-
- This number is used to construct the address of a radio paging
- server, which forms the recipient address for the message, e.g., one
- of:
-
- pager.ATOM@6.7.7.8.0.4.9.5.1.4.1.tpc.int
- pager-alpha.ATOM@6.7.7.8.0.4.9.5.1.4.1.tpc.int
- pager-numeric@6.7.7.8.0.4.9.5.1.4.1.tpc.int
-
- where "ATOM" is an RFC 822 atom [1], an opaque string for use in
- recipient identification when communicating with the paging network,
- and the domain-part is constructed by reversing the telephone number,
- converting each digit to a domain-label, and being placed under
- "tpc.int". (The telephone number must not include any international
- access codes.)
-
- Note that the mailbox syntax is purposefully restricted in the
- interests of pragmatism. To paraphrase STD 11, RFC 822, an atom is
- defined as:
-
- atom = 1*atomchar
-
- atomchar= <any upper or lowercase alphabetic character
- (A-Z a-z)>
- / <any digit (0-9)>
- / "!" / "#" / "$" / "%" / "&" / "'" / "*" / "+"
- / "-" / "/" / "=" / "?" / "^" / "_" / "`" / "{"
- / "|" / "}" / "~"
-
- Finally, note that some Internet mail software (especially gateways
- from outside the Internet) impose stringent limitations on the size
- of a mailbox-string. Thus, originating user agents should take care
- in limiting the local-part to no more than 70 or so characters.
-
-
-
-
-
- Rose [Page 2]
-
- RFC 1703 Radio Paging -- Technical Procedures October 1994
-
-
- 2.2. Routing
-
- The message is routed in exactly the same fashion as all other
- electronic mail, i.e., using the MX algorithm [2]. Since a radio
- paging server might be able to access many radio pagers, the
- wildcarding facilities of the DNS [3,4] are used accordingly. For
- example, if a radio paging server residing at "dbc.mtview.ca.us" is
- willing to access any radio pager with a telephone number prefix of
-
- +1 415 940
-
- then this resource record might be present
-
- *.0.4.9.5.1.4.1.tpc.int. IN MX 10 dbc.mtview.ca.us.
-
- Naturally, if several radio paging servers were willing to access any
- radio pager in that prefix, multiple MX resource records would be
- present. (The DNS servers for the TPC.INT subdomain perform a
- rudimentary form of load balancing by rotating the order of the MX
- records returned on each query.)
-
- It should be noted that the presence of a wildcard RR which matches a
- radio paging server's address does not imply that the corresponding
- telephone number is valid, or, if valid, that a radio pager is
- identified by the phone number. Rather, the presence of a wildcard
- RR indicates that a radio paging server is willing to attempt access.
-
- 3. Procedure
-
- When information is to be sent to a radio pager, the user application
- constructs an RFC 822 message, containing a "Message-ID" field and a
- textual content (e.g., a "text/plain" content [5]).
-
- The message is then sent to the radio paging server's electronic mail
- address. The radio paging server begins by looking at the local part
- of the address.
-
- 3.1. Alpha-numeric Radio Pagers
-
- If the local-part is either "pager.ATOM" or "pager-alpha.ATOM" then
- this indicates that the recipient is using an alpha-numeric radio
- pager, and ATOM either identifies a paging network (CARRIER), or a
- radio pager identity number (PIN), or both, according to these rules:
-
- (1) if ATOM consists entirely of numeric characters, then ATOM is a
- PIN, and the domain-part refers to the IXO access telephone
- number for a radio paging carrier; otherwise,
-
-
-
-
- Rose [Page 3]
-
- RFC 1703 Radio Paging -- Technical Procedures October 1994
-
-
- (2) if ATOM does not contain a hyphen character ("-"), then ATOM is
- a CARRIER, a local database is consulted to determine the
- corresponding IXO access telephone number, and the telephone
- number corresponding to the domain-part is used to identify the
- radio pager; otherwise,
-
- (3) if ATOM does contain a hyphen character ("-"), then everything
- to the left of the first hyphen is a CARRIER, and everything to
- the right of that hyphen is a PIN, a local database is consulted
- to determine the corresponding IXO access telephone number, and
- the PIN is used is used to identify the radio pager.
-
- If the local-part starts with "pager.", then the message sent to the
- radio pager consists of the body of the message; otherwise, if the
- local-part starts with "pager-alpha.", then the radio paging server
- determines which information in the headers and body of the message
- are used when constructing the paging message. For example, some
- radio paging servers might choose to examine the "To" and "Subject"
- fields, in addition to the body, whilst other radio paging servers
- might choose to simply send the body verbatim.
-
- 3.2. Numeric Radio Pagers
-
- If the local-part is the literal string "pager-numeric" then this
- indicates that the recipient is using a numeric pager, and the radio
- pager dials the telephone number corresponding to the domain-part.
-
- The message sent to the radio pager consists of the body of the
- message, which must consist solely of digits.
-
- 3.3. MAILing versus SENDing
-
- An SMTP client communicating with a radio paging server may use
- attempt either the MAIL or SEND command. The radio paging server
- MUST support the MAIL command, and MAY support any of the SEND, SOML,
- or SAML commands.
-
- If the MAIL command is used, then a positive completion reply to both
- the RCPT and DATA commands indicates, at a minimum, that the message
- has been queued for transmission into the radio paging network for
- the recipient, but is at least queued for transmission into the radio
- paging network.
-
- If the SEND command is used, then a positive completion reply to both
- the RCPT and DATA commands indicates that the message has been
- accepted by the radio paging network for delivery to the recipient.
-
-
-
-
-
- Rose [Page 4]
-
- RFC 1703 Radio Paging -- Technical Procedures October 1994
-
-
- If the SOML or SAML command is used, then a positive completion reply
- to both the RCPT and DATA commands indicates that the message may
- have been accepted by the radio paging network for delivery to the
- recipient.
-
- 3.4. Latency
-
- Although the Internet electronic mail service tends to perform
- delivery in a timely and reliable manner, some paging services will
- wish to provide a higher degree of assurance to their clients, in
- particular guaranteeing that a positive reply code means that the
- page has been sent on the radio paging network. For such
- requirements, the primary constraints are server implementation and
- client/server network connectivity.
-
- A client that uses the SEND or SAML commands is explicitly requesting
- real-time transmission on the radio paging network and is requiring
- that the server reply code will carry a statement of success or
- failure about that transmission.
-
- The IP level of the Internet performs datagram store-and-forward
- service, but gives the end system hosts the appearance of direct
- connectivity, by virtue of allowing interactive service. The
- Internet electronic mail service adds another layer of store-and-
- forward indirection, so that messages may go through any number of
- relays (and/or gateways). This may introduce arbitrarily large
- delays of minutes, hours, or days.
-
- A client that configures their Internet attachment to permit "direct"
- SMTP connectivity to a radio paging server will be able to submit
- paging requests to the server directly, without additional SMTP-
- relaying. That is, transmission from radio paging client to server
- will be one "SMTP-hop"only. This will eliminate any possibility of
- non-deterministic delay by the Internet itself.
-
- The combination of configuring radio paging server and client to
- allow direct IP/SMTP-level interaction and ensuring that they use
- SEND or SAML commands only will mean that a client receiving a
- positive reply from the server is assured that the page has been sent
- on the radio paging network.
-
- 4. Usage Examples
-
- These examples make use of the "iddd.tpc.int" subdomain. The DNS
- servers for this subdomain, upon encountering a domain of the form:
-
- NUMBER.iddd.tpc.int
-
-
-
-
- Rose [Page 5]
-
- RFC 1703 Radio Paging -- Technical Procedures October 1994
-
-
- automatically create a CNAME RR of the form:
-
- R.E.B.M.U.N.iddd.tpc.int
-
- e.g.,
-
- 14159408776.iddd.tpc.int
-
- will be treated as
-
- 6.7.7.8.0.4.9.5.1.4.1.tpc.int
-
- 4.1. A MIME Example
-
- To: pager-alpha.98765@18005551234.iddd.tpc.int
- cc: Marshall Rose <mrose@dbc.mtview.ca.us>
- From: Carl Malamud <carl@malamud.com>
- Date: Thu, 22 Jul 1993 08:38:00 -0800
- Subject: First example, for an alphanumeric pager
- Message-ID: <19930908220700.1@malamud.com>
- MIME-Version: 1.0
- Content-Type: text/plain; charset=us-ascii
-
- A brief textual message sent to the radio paging network
- having an IXO access telephone number of "+1-8005551234"
- to the radio pager having a PIN of "98765".
-
- 4.2. A Non-MIME Example
-
- To: pager-numeric@14159408776.iddd.tpc.int
- From: Carl Malamud <carl@malamud.com>
- Date: Thu, 22 Jul 1993 08:38:00 -0800
- Subject: Second example, for a numeric pager
- Message-ID: <19930908220700.2@malamud.com>
-
- 2026282044
-
- 5. Server Configuration Example
-
- A hypothetical radio paging carrier, e.g.,
-
- Pigeon Paging
-
- might choose to integrate its radio paging services with Internet e-
- mail in the following fashion:
-
-
-
-
-
-
- Rose [Page 6]
-
- RFC 1703 Radio Paging -- Technical Procedures October 1994
-
-
- (1) The radio paging carrier establishes a top-level domain name,
- e.g.,
-
- pigeon.net
-
- (2) The radio paging carrier installs and operates one or more
- radio paging servers, each having a unique entry in the DNS,
- e.g.,
-
- ixo1.pigeon.net. IN A a.b.c.d
-
- Each of these radio paging servers runs an SMTP server which
- implements the SEND command as described in Section 3.3 above.
-
- (3) The radio paging carrier coordinates with the administrators of
- the TPC.INT subdomain to have the appropriate MX records added
- to the DNS, assigning cost values in the MX records to reflect
- any difference in the quality of service between the radio
- paging servers, e.g.,
-
- 4.3.2.1.5.5.5.0.0.8.1.tpc.int. IN MX 5 ixo1.pigeon.net.
- 4.3.2.1.5.5.5.0.0.8.1.tpc.int. IN MX 5 ixo2.pigeon.net.
-
- which would provide both load-balancing and redundancy
- (particularly if the servers were located at different points in
- the Internet). At this point, messages can be sent using the
- addressing formats described in Section 2.2 above.
-
- (4) The radio paging carrier may choose to make available a client
- program which uses the SMTP SEND command, in order to achieve
- "real-time" delivery of messages into the radio paging network.
-
- (5) Finally, the radio paging carry may choose to assign each of its
- customers a mailbox, e.g.,
-
- mrose@pager.pigeon.net
-
- which maps to the TPC.INT address for the customer's radio pager.
-
- The system(s) listed in the DNS for this domain would maintain
- the appropriate mail aliases for this mapping, e.g.,
-
- R: 220 pager.pigeon.net SMTP ready
- S: HELO malamud.com
- R: 220 pager.pigeon.net
- S: EXPN mrose
- R: 250 <pager-alpha.98765@18005551234.iddd.tpc.int>
-
-
-
-
- Rose [Page 7]
-
- RFC 1703 Radio Paging -- Technical Procedures October 1994
-
-
- At the carrier's discretion, these systems may also be the
- systems running the radio paging servers. However, this needn't
- be the case. For example, consider a situation where a client
- program which uses the SMTP SEND command, wants to ensure that it
- is talking to radio paging server for an address: e.g.,
-
- R: 220 pager.pigeon.net SMTP ready
- S: EHLO malamud.com
- R: 220-pager.pigeon.net
- R: 220 SEND
- S: VRFY mrose
- R: 551 User not local;
- try <pager-alpha.98765@18005551234.iddd.tpc.int>
-
- or
-
- R: 220 pager.pigeon.net SMTP ready
- S: EHLO malamud.com
- R: 220-pager.pigeon.net
- R: 220 SEND
- S: VRFY mrose
- R: 250 <pager-alpha.98765@18005551234.iddd.tpc.int>
-
- 6. Security Considerations
-
- Internet mail may be subject to monitoring by third parties, and in
- particular, message relays.
-
- 7. Acknowledgements
-
- This document was motivated by RFC 1568 [6] and RFC 1645 [7]. In
- addition, David Crocker, Carl Malamud, and Perry Metzger also
- provided substantive comments.
-
- 8. References
-
- [1] Crocker, D., "Standard for the Format of ARPA Internet Text
- Messages", STD 11, RFC 822, University of Delaware, August 1982.
-
- [2] Partridge, C., "Mail Routing and the Domain System", BBN
- Laboratories, STD 14, RFC 974, BBN, January 1986.
-
- [3] Mockapetris, P., "Domain Names -- Concepts and Facilities", STD
- 13, RFC 1034, USC/Information Sciences Institute, November 1987.
-
- [4] Mockapetris, P., "Domain Names -- Implementation and
- Specification", STD 13, RFC 1035, USC/Information Sciences
- Institute, November 1987.
-
-
-
- Rose [Page 8]
-
- RFC 1703 Radio Paging -- Technical Procedures October 1994
-
-
- [5] Borenstein, N., and N. Freed, "MIME: Mechanisms for Specifying
- and Describing the Format of Internet Message Bodies", RFC 1521,
- Bellcore, Innosoft, September 1993.
-
- [6] Gwinn, A., "Simple Network Paging Protocol - Version 1(b)", RFC
- 1568, Southern Methodist University, January 1994.
-
- [7] Gwinn, A., "Simple Network Paging Protocol - Version 2", RFC
- 1645, Southern Methodist University, July 1994.
-
- 9. Author's Address
-
- Marshall T. Rose
- Dover Beach Consulting, Inc.
- 420 Whisman Court
- Mountain View, CA 94043-2186
- US
-
- Phone: +1 415 968 1052
- Fax: +1 415 968 2510
- EMail: mrose@dbc.mtview.ca.us
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- Rose [Page 9]
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