North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical Re: SMS Standards
On Thu, Oct 16, 2008 at 9:41 PM, Bruce Pinsky <[email protected]> wrote: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > Glen Kent wrote: >> Hi, >> >> Apologies in advance since this is off-topic. However, posting in on >> nanog since i am confident that we will have some experts who would be >> able to guide me here. >> >> I want to study the standards (RFC equivalent) for sending and >> receiving SMSs. Any ideas on what kind of protocol runs between a >> mobile phone and a SMS center (SMSC)? >> > > Wiki_Pedia is your friend http://en.wikipedia.org/wiki/Short_message_service > > The Short Message Service - Point to Point (SMS-PP) is defined in GSM > recommendation 03.40.[2] GSM 03.41 defines the Short Message Service - Cell > Broadcast (SMS-CB) which allows messages (advertising, public information, > etc.) to be broadcast to all mobile users in a specified geographical > area.[16] Messages are sent to a Short Message Service Centre (SMSC) which > provides a store-and-forward mechanism. It attempts to send messages to > their recipients. If a recipient is not reachable, the SMSC queues the > message for later retry.[17] Some SMSCs also provide a "forward and forget" > option where transmission is tried only once. Both Mobile Terminated (MT), > for messages sent to a mobile handset, and Mobile Originating (MO), for > those that are sent from the mobile handset, operations are supported. > Message delivery is best effort, so there are no guarantees that a message > will actually be delivered to its recipient and delay or complete loss of a > message is not uncommon, particularly when sending between networks. Users > may choose to request delivery reports (simply add *0# or *N# to the > beginning of your text message), which can provide positive confirmation > that the message has reached the intended recipient. > > Transmission of short messages between the SMSC and the handset is done > using the Mobile Application Part (MAP) of the SS7 protocol. Messages are > sent with the MAP mo- and mt-ForwardSM operations, whose payload length is > limited by the constraints of the signalling protocol to precisely 140 > octets (140 octets = 140 * 8 bits = 1120 bits). Short messages can be > encoded using a variety of alphabets: the default GSM 7-bit alphabet (shown > below), the 8-bit data alphabet, and the 16-bit UTF-16/UCS-2 alphabet.[18] > Depending on which alphabet the subscriber has configured in the handset, > this leads to the maximum individual Short Message sizes of 160 7-bit > characters, 140 8-bit characters, or 70 16-bit characters (including > spaces). Support of the GSM 7-bit alphabet is mandatory for GSM handsets > and network elements,[18] but characters in languages such as Arabic, > Chinese, Korean, Japanese or Cyrillic alphabet languages (e.g. Russian) > must be encoded using the 16-bit UCS-2 character encoding (see Unicode). > Routing data and other metadata is additional to the payload size. > > - -- > ========= > bep > > -----BEGIN PGP SIGNATURE----- > Version: GnuPG v1.4.9 (MingW32) > Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org > > iEYEARECAAYFAkj37WcACgkQE1XcgMgrtyZiVACgjSYOrHVRE9g1vufxWpa67rC6 > o8YAn1JjliEYx73fLGXbIOyeTTZtsj/S > =2vZP > -----END PGP SIGNATURE----- > Depending on what you are doing, see also SMPP protocol as much inter-carrier SMS is carried over SMPP links. Also many external content providers send SMS messages to phones via SMPP to reach the carrier (news alerts, etc). http://en.wikipedia.org/wiki/Short_message_peer-to-peer_protocol www.alvento.com/productos/sms/smpp/smpp34.pdf John B
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