Hi, I've been looking at the spec 03.40 and I've also tested and 154 is the max amount of chars you can use before becoming another SMS.
If I re-read the spec below with this information, can I assume Kannel is using compressed GSM Default alphabet 7 bit data and you always lose 6 octets to give you 134 octets left which translates into 154 chars.? (If it was using uncompressed GSM Default 7 bit data then you would only have 153 chars per concatenated SMS.) Is my understanding correct? 9.2.3.24.1 Concatenated Short Messages This facility allows short messages to be concatenated to form a longer message. In the case of uncompressed 8?bit data, the maximum length of the short message within the TP?UD field is 134 (140?6) octets. In the case of uncompressed GSM Default 7 bit data, the maximum length of the short message within the TP?UD field is 153 (160?7) characters. In the case of 16 bit uncompressed USC2 data, the maximum length of the short message within the TP?UD field is 67 ((140?6)/2) characters. A UCS2 character must not be split in the middle; if the length of the User Data Header is odd, the maximum length of the whole TP-UD field is 139 octets. In the case of compressed GSM Default alphabet 7 bit data, 8 bit data or UCS2 the maximum length of the compressed short message within the TP-UD field is 134 ( 140-6) octets including the Compression Header and Compression Footer, both or either of which may be present ( See subclause 3.9). The maximum length of an uncompressed concatenated short message is 39015 (255*153) default alphabet characters, 34170 (255*134) octets or 17085 (255*67) UCS2 characters. Thanks for your great response. Rgds
