Project SMSLink - PDU Format Support

Please note: the purpose of the present document is not to provide a full tutorial on how to use the PDU format, nor is it a reprint of the PDU protocol spec. If you're looking for the latter, please refer to the ETSI GSM 03.40 standard, available for download from ETSI's website. There is also a very detailed description of the PDU format and its quirks available here, presented in a way that make it a lot easier to understand than ETSI's raw specs (please see also my related links section for links to sites with more info on PDU format).

Rather, the purpose of this page is to provide as accurate an information as I can on the level of support for the numerous PDU format features and quirks within SMSLink.

Table of Contents

• PDU string structure summary.
• <numplan> support.
• Data Coding Scheme (<dcs>) support.

PDU string structure summary.

TBD

<numplan> support.

The <numplan> field defines the context within which the next field, <oa> or "originating address", has to be understood. The most common numplans are 0x81 (local numbering scheme) or 0x91 (international numbering scheme).

But of course, there are situations where the originating address has to be hidden, or is meaningless, such as when the message was sent from a website. There will, of course, be other cases, but those are the ones we're aware of (thanks to the kind help of Thomas Gutzler).

<numplan> values supported in reception mode

Notes:
¹: The actual contents of the <oa> field will be logged through syslog at the "notice" level before being zeroed out.
²: cf. <numplan> 0x85 -- handled in the same way.
³: Most often. Or any other short string to the choosing of the site's administrator.
⁴: Support included as of ver. 0.55b.

<numplan> values supported in sending mode

Data Coding Scheme (<dcs>) support.

At present, only DCS_PCCP437 is supported. More on this TBD.