[asterisk-dev] ISDN Userfield UUI has a length constraint?

[Richard Mudgett]

On Mon, Jun 16, 2014 at 3:03 PM, Yves A. <yves030 at gmx.de> wrote:

> Hello List,
>
> I made the changes in the q931.c sourcefile and got rid of the 35
> character constraint.
> thanks for your attention.
> yves
>
> Am 16.06.2014 15:23, schrieb Yves A.:
>
>  seems, I found the right place by myself... no wonder I could not find it
>> in asterisk sources....
>> the constraint is located in the sources of libpri.... I will change
>> that, recompile and post feedback here...
>>
>> thanks anyways,
>> yves
>>
>> Am 16.06.2014 14:57, schrieb Yves A.:
>>
>>> Hi,
>>>
>>> I am using the Q931 / ISDN USER-USER-INFO field for transferring data
>>> between the caller and the called party.
>>> This works fine as long as the information does not exceed 35
>>> characters...
>>> Unfortunately sometimes I need more space and due to the Q931 Specs I
>>> think there should be space for max. 128 octets (bytes/characters)...
>>> Can someone point me to the place in the sources where I can check and
>>> adopt this?
>>> I have tested this on an asterisk 11.3 and on an asterisk 1.6.2.24....
>>> both show the same limit of 35 characters...
>>>
>>
That restriction has been there since the feature was put into the code.
This would be the reason for the 35 character restriction:

ITU Q.931 Section 4.5.30:
{quote}
In USER INFORMATION messages sent in association with a circuit-mode
connection, the User-
user information element has a network dependent maximum size of 35 or 131
octets. For USER
INFORMATION messages sent in a temporary or permanent user-user signalling
connection, the
user information field contained inside this information element has a
maximum size equal to the
maximum size of messages defined in clause 3, that is 260 octets.
{quote}

Richard
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.digium.com/pipermail/asterisk-dev/attachments/20140616/d8c05d67/attachment-0001.html>