gsup: Document passing MSISDN as part of the response
When asking the GGSN to create/open a PDP context one needs
to send a MSISDN. The MSISDN can only be provided through the
GSUP interface.
diff --git a/openbsc/doc/sgsn-remote-protocol.txt b/openbsc/doc/sgsn-remote-protocol.txt
index 3369d19..27b9abf 100644
--- a/openbsc/doc/sgsn-remote-protocol.txt
+++ b/openbsc/doc/sgsn-remote-protocol.txt
@@ -119,6 +119,7 @@
IEI Info Element Type Pres. Format Length
Message type 4.2.1 M V 1
01 IMSI 4.2.9 M TLV 2-10
+ 08 MSISDN 4.2.10 O TLV 0-9
04 PDP info complete 4.2.8 O TLV 2
05 PDP info 4.2.3 1-10 TLV
@@ -354,6 +355,7 @@
| 0x05 PDP info 4.2.3 |
| 0x06 Cancel type 4.2.6 |
| 0x07 Freeze P-TMSI 4.2.8 |
+ | 0x08 MSISDN ISDN-AddressString/octet, 4.2.10 |
| 0x10 PDP context id big endian int |
| 0x11 PDP type 4.2.4 |
| 0x12 APN 04.08, 10.5.6.1 |
@@ -397,3 +399,24 @@
Note 1) Either '1 1 1 1 | Number digit N' (N odd) or
'Number digit N | Number digit N-1' (N even),
where N is the number of digits.
+
+4.2.10. ISDN-AddressString / MSISDN / Called Party BCD Number
+
+The MSISDN is encoded as an ISDN-AddressString in GSM 09.02 and Called Party
+BCD Number in GSM 04.08. It will be stored by the SGSN and then passed as is
+to the GGSN during the activation of the primary PDP Context.
+
+ 8 7 6 5 4 3 2 1
+ +-----------------------------------------------------+
+ | | IEI | octet 1
+ +-----------------------------------------------------+
+ | Length of IE contents | octet 2
+ +-----------------------------------------------------+
+ | ext | Type of num | Numbering plan | octet 2
+ +-----------------------------------------------------+
+ | Number digit 2 | Number digit 1 | octet 3
+ +-----------------------------------------------------+
+ | Number digit 4 | Number digit 3 | octet 4
+ +-----------------------------------------------------+
+ : : :
+ +-----------------------------------------------------+