Talk:Unstructured Supplementary Service Data

message: Does anyone know what the CDMA equivalent of GSM is ? Kendirangu 11:35, 4 January 2007 (UTC)
thread_title:  CDMA equivallent. 

message: I could not find any reference to USSD in Ducont web site, is it obsolete product ? I googled "SMS site:www.ducont.com" nothind returned from this search
You can visit : https://www.facebook.com/USSD2  — Preceding unsigned comment added by Mohitmehral (talk • contribs) 08:08, 28 November 2013 (UTC)
thread_title:  Companies working on USSD 

message: I removed the telnet-mail analogy, because it requires the reader to know what telnet is, which relatively few people will know, and also because in my opinion it is not a very accurate analogy. Captain Chaos (talk) 16:00, 15 October 2009 (UTC)
thread_title:  Removed telnet-mail analogy 

message: This is a poor article because it does not say what USSD actuall *is*. It says it is "a capability of all GSM phones", and is "generally associated with real-time or instant messaging type phone services", and that it has "no store-and-forward capability such as is typical of other short-message protocols" - but none of these tell me what it *actually is* - except for the last statement, which implies that it is "a short-message protocol". Right? wrong? Could someone knowledgeable clearly describe what it *actually is*? TC 203.122.223.121 (talk) 11:00, 4 April 2010 (UTC)
replies: text: I hope the information I added during my copy-edit clears things up for you! Macwhiz (talk) 21:13, 23 August 2010 (UTC)
thread_title:  what IS it? 

message: Completed a copy-edit.  Brought the sections into compliance with the Manual of Style.  Added more information from a new reference to clarify the topic.  Deleted some redundant or otherwise semantically null sentences.   The article now reads like an encyclopedia entry; Wikipedia articles should not substitute for technical documentation, but be written for the lay person, per the Guidelines. Macwhiz (talk) 21:12, 23 August 2010 (UTC)
thread_title:  Copy edit 

message: I think we need to describe what the example codes actually mean.
Example USSD codes:
*101# 
*109*72348937857623#
That is going to be a bit hard, as it depends only on the network provider... Might mean one thing with one provider and something completely different with another - 130.149.154.39 (talk) 12:24, 19 November 2007 (UTC)
replies: text: I'm not sure it'd be appropriate for Wikipedia; it seems like that could very quickly become a list of miscellaneous information, which would then run against the "What Wikipedia is not" principles. I agree it would be useful information, just not perhaps useful in an encyclopedia.  Perhaps such a thing would be best put up on Wikibooks or another site? // ⌘macwhiz (talk) 16:54, 5 September 2010 (UTC)
replies: text: There seems to be a standard or at least a de facto standard for USSD codes, e.g. many operators support *101# for account-related information. Is there actually some specification for often-used codes? A short summary about and a link to such specification would be a good addition to this article. --Abdull (talk) 15:33, 28 December 2010 (UTC)
thread_title:  Table of known USSD codes 

message: Does the mysterious line about "cucumber-based" services mean something, or did somebody just vandalized the page?  — Preceding unsigned comment added by 85.174.241.218 (talk) 04:05, 8 August 2012 (UTC)
thread_title:  "cucumber-based"?? 

message: Example USSD codes: 
*  - display's user's balance on the Vodafone network
*  - display's customer care on the Vodafone network
*  - display's user's balance on the Airtel,IDEA network
*  - INDIAN Railways passenger inquiry short-code on the all operators network.
*  - display's Indian railway PNR inquiry results, short-code working across all the Indian operators network.
*  - Facebook on USSD, working most of the countries, across all the GSM operators.
*  - State Bank of India USSD banking service.
--Mohitmehral (talk) 07:59, 28 November 2013 (UTC)
thread_title:  Examples moved from article

message: http://berlin.ccc.de/~tobias/mmi-ussd-ss-codes-explained.html
I have quoted the whole web page, in case the link is lost in future.
The recent Samsung remote wipe attack got a lot of media coverage. In every article and blog post you could read that the attack made use of an "USSD code".
But that is not the case.
So what are the codes with those */# characters called and what is an USSD code?
Every code that you enter over your phones keypad that contains asterisk (*) or hash (#) characters is an MMI code. MMI stands for Man-Machine-Interface.
Even though most of these MMI codes look pretty similar, they fall into different groups with completely different actions. Some are just used locally on the device, some are sent to the SIM, others are sent to the network.
Different kinds of MMI codes
Supplementary Service (SS) codes
Those are the codes used to control, for example, call forwarding or number presentation.
With *21*123456789# <SEND> you would instruct your phone to ask the network to forward all your incoming calls to the number 123456789. But this code is not sent directly to the network. Instead, it is parsed by the phone which then constructs an ASN.1 coded request to the network.
These codes are hardcoded into every GSM/UMTS/LTE device worldwide and cannot be changed by your network operator.
Unstructured Supplementary Service Data (USSD) codes
If you enter a code that at least ends in a hash sign (and press <SEND>) and is not recognized by the phones MMI parser, the code will be sent to the network verbatim. It then depends on the network if this code is supported. One of the most used cases is a code for prepaid cards to check your balance. Many networks use something like *#100#. But it is really the choice of the network operator which code to use as long as it not already taken.
So entering *20*1234# <SEND> or *21*1234# <SEND> would do two completely different things: The first code would be sent as-is to the network for further processing (most likely returning an error), while the second code would be parsed by the phone and a structured request for activation of call forwarding would be sent to the network.
Please note: For SS and USSD codes you always need to press the <SEND> key after entering them, so it is not possible to automatically execute those codes with a tel-URL.
Manufacturer defined MMI codes
This is the category into which the much talked-about Samsung code falls.
Codes specific to your phone model that have been built in by the manufacturer to, for example, activate service menus or reset the device. These codes also contain * and # characters. Since the codes are not being sent to the network, you don’t have to press the <SEND> key at the end – they are executed as soon as the last digit or character has been entered. There is one code that is mandatory for all manufacturers of GSM/UMTS/LTE phones to implement:*#06#
It shows the devices IMEI (Internatiol Mobile Equipment Identifier)
SIM control codes
These codes are used, for example, to change your SIMs PIN code.
  **04*1234*6789*6789# would change your PIN code from "1234" to "6789".
These codes are also executed without pressing the <SEND> key.
The complete specification for the MMI interface of GSM/UMTS/LTE devices can be found in 3GPP TS 22.030: "Man-Machine Interface (MMI) of the User Equipment (UE)"
JohnI (talk) 23:08, 17 December 2014 (UTC)
thread_title:  What’s the difference between USSD, MMI and SS codes? 

message: Nice Crfariasb (talk) 08:59, 6 January 2017 (UTC)
thread_title:  Cf 

message: Propose moving §Code table to the article Supplementary service codes as it is unrelated to USSD and is actually a supplementary service code. In addition, marking all codes with  for easier identification. waddie96 ★ (talk) 08:02, 28 January 2022 (UTC)
thread_title:  Propose moving [[Unstructured_Supplementary_Service_Data#Code_table|§Code table]]