Subject: [dispatch] Call management and USSD

From: "Anton Tveretin" <[email-masked]>
Date: Thu, 19 Sep 2013 01:35:10 +0600

Dear All,
The term USSD is used to the 2 different things.
The first one is formally called "Man-Machine interface", 3GPP 22.030.
Informally, they use "USSD codes". Examples... Of course, some codes to not
need any network traffic, and others are implemented with USSD (see below).
The second one is 3GPP 24.008, and associated functions of MAP (29.002). It
is called "Unstructured supplementary services data" (USSD) and actualy
defines a bearer, similar to D-channel bearer of ISDN. The are examples of
its usage as of bearer (WAP), unassociated from MMI.
Since early versions of H.323, HTTP is suggested for network-level 
supplementary service handling. However, ISTM that there are no standard 
URLs, and user has to navigate through pages.
Common way to manage calls (activate or deactivate call forwarding, for 
instance) allows to use alternative approaches (e.g. menu) that is 
device-specific and not provider-specific.
I suggest making a list of services not mentioned in 22.030 (I would add CUG 
management, AOC activation and "probing" i.e. checking cost of call without 
actually making it, and billing-related).
Later, I think there should be either standard URLs, or SIP dialogs used 
(again, with standard URLs).
Sincerely yours, Anton.

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From: "DRAGE, Keith (Keith)" <[email-masked]>
Date: Thu, 19 Sep 2013 16:35:57 +0000

For USSD see:

ftp://ftp.3gpp.org/Specs/html-info/24390.htm 

As far as I am aware USSD is used only by mobile operators, which presumably have no H.323 deployment.

In regard to supplementary service management, see:

ftp://ftp.3gpp.org/Specs/html-info/24623.htm 

There is also 

ftp://ftp.3gpp.org/Specs/html-info/24238.htm 

which uses dialstrings, but does not specify them.

regards

Keith

> -----Original Message-----
> From: [email-masked] [mailto:[email-masked]] On
> Behalf Of Anton Tveretin
> Sent: 18 September 2013 20:35
> To: [email-masked]
> Subject: [dispatch] Call management and USSD
> 
> Dear All,
> _______________________________________________
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---

From: "Anton Tveretin" <[email-masked]>
Date: Mon, 23 Sep 2013 22:56:48 +0600

That's what I want to change. :)
"As far as I am aware USSD is used only by mobile operators, which 
presumably have no H.323 deployment."

Also, I think there should be a code for 3pcc. Namely, to trust third party 
to initiate calls, and to get list of trustees or trustors. This also covers 
"doctor" scenario discussed in STIR.

I noticed that many phones (incl. softphones) still use numeric keyboard, so 
it is a good idea to use numeric codes.

As an example implementation:
1. REGISTER response contains an URL (http(s):, wap:, sip(s):, etc).
2. When user inputs an MMI code, dispatch it as text/plain body to that URL, 
or alternatively transform that URL (for further study).
3. Process response. This may start a SIP dialog or cookie-based HTTP 
session, or complete in a single transaction.
4. Further exchange messages.
5. Terminate the dialog on user action.

----- Original Message ----- 
From: "DRAGE, Keith (Keith)" <[email-masked]>
To: "Anton Tveretin" <[email-masked]>; <[email-masked]>
Sent: Thursday, September 19, 2013 10:35 PM
Subject: RE: [dispatch] Call management and USSD

For USSD see:

There is also

regards

Keith