diff --git a/openbsc/doc/control-interface.txt b/openbsc/doc/control-interface.txt
deleted file mode 100644
index b43cafc..0000000
--- a/openbsc/doc/control-interface.txt
+++ /dev/null
@@ -1,21 +0,0 @@
-The protocol for the control interface is wrapped inside the ip.access header
-with the IPAC_PROTO_OSMO protocol ID (0xee). Inside the ip.access header is
-a struct ipaccess_head_ext with protocol ID 0x00 which indicates the control
-interface.
-
-After that the actual protocol is text based:
-
-* Getting the value of a variable
--> GET <id> <var>
-<- GET_REPLY <id> <var> <val>
-or ERROR <id> <reason>
-
-* Setting the value of a variable
--> SET <id> <var> <val>
-<- SET_REPLY <id> <var> <val>
-or ERROR <id> <reason>
-
-* A value changes which triggers a trap
-<- TRAP <var> <val>
-
-<id> needs to be unique within a connection. '0' is not allowed
diff --git a/openbsc/doc/osmocom-authn-protocol.txt b/openbsc/doc/osmocom-authn-protocol.txt
deleted file mode 100644
index 1b6794e..0000000
--- a/openbsc/doc/osmocom-authn-protocol.txt
+++ /dev/null
@@ -1,250 +0,0 @@
-
-               Osmocom Authentication Protocol (OAP)
-
-1. General
-
-The Osmocom Authentication Protocol employs mutual authentication to register a
-client with a server over an IPA connection. Milenage is used as the
-authentication algorithm, where client and server have a shared secret.
-
-For example, an SGSN, as OAP client, may use its SGSN ID to register with a MAP
-proxy, an OAP server.
-
-1.1. Connection
-
-The protocol expects that a reliable, ordered, packet boundaries preserving
-connection is used (e.g. IPA over TCP).
-
-1.2. Using IPA
-
-By default, the following identifiers should be used:
-  - IPA protocol: 0xee (OSMO)
-  - IPA OSMO protocol extension: 0x06 (OAP)
-
-2. Procedures
-
-Ideal communication sequence:
-
-   Client                               Server
-     |                                    |
-     |  Register (ID)                     |
-     |----------------------------------->|
-     |                                    |
-     |  Challenge (RAND+AUTN)             |
-     |<-----------------------------------|
-     |                                    |
-     |  Challenge Result (XRES)           |
-     |----------------------------------->|
-     |                                    |
-     |  Register Result                   |
-     |<-----------------------------------|
-
-Variation "test setup":
-
-   Client                               Server
-     |                                    |
-     |  Register (ID)                     |
-     |----------------------------------->|
-     |                                    |
-     |  Register Result                   |
-     |<-----------------------------------|
-
-Variation "invalid sequence nr":
-
-   Client                               Server
-     |                                    |
-     |  Register (ID)                     |
-     |----------------------------------->|
-     |                                    |
-     |  Challenge (RAND+AUTN)             |
-     |<-----------------------------------|
-     |                                    |
-     |  Sync Request (AUTS)               |
-     |----------------------------------->|
-     |                                    |
-     |  Challenge (RAND'+AUTN')           |
-     |<-----------------------------------|
-     |                                    |
-     |  Challenge Result (XRES)           |
-     |----------------------------------->|
-     |                                    |
-     |  Register Result                   |
-     |<-----------------------------------|
-
-2.1. Register
-
-The client sends a REGISTER_REQ message containing an identifier number.
-
-2.2. Challenge
-
-The OAP server (optionally) sends back a CHALLENGE_REQ, containing random bytes
-and a milenage authentication token generated from these random bytes, using a
-shared secret, to authenticate itself to the OAP client. The server may omit
-this challenge entirely, based on its configuration, and immediately reply with
-a Register Result response. If the client cannot be registered (e.g. id is
-invalid), the server sends a REGISTER_ERR response.
-
-2.3. Challenge Result
-
-When the client has received a Challenge, it may verify the server's
-authenticity and validity of the sequence number (included in AUTN), and, if
-valid, reply with a CHALLENGE_RES message. This shall contain an XRES
-authentication token generated by milenage from the same random bytes received
-from the server and the same shared secet. If the client decides to cancel the
-registration (e.g. invalid AUTN), it shall not reply to the CHALLENGE_REQ; a
-CHALLENGE_ERR message may be sent, but is not mandatory. For example, the
-client may directly start with a new REGISTER_REQ message.
-
-2.4. Sync Request
-
-When the client has received a Challenge but sees an invalid sequence number
-(embedded in AUTN, according to the milenage algorithm), the client may send a
-SYNC_REQ message containing an AUTS synchronisation token.
-
-2.5. Sync Result
-
-If the server has received a valid Sync Request, it shall answer by directly
-sending another Challenge (see 2.2.). If an invalid Sync Request is received,
-the server shall reply with a REGISTER_ERR message.
-
-2.6. Register Result
-
-The server sends a REGISTER_RES message to indicate that registration has been
-successful. If the server cannot register the client (e.g. invalid challenge
-response), it shall send a REGISTER_ERR message.
-
-3. Message Format
-
-3.1. General
-
-Every message is based on the following message format
-
-  IEI	Info Element		Type			Pres.	Format	Length
-	Message type		4.2.1			M	V	1
-
-The receiver shall be able to receive IEs in any order. Unknown IEs shall be
-ignored.
-
-3.2.1. Register Request
-
-Client -> Server
-
-  IEI	Info Element		Type			Pres.	Format	Length
-	Message type		4.2.1			M	V	1
-  30	Client ID		big endian int (2 oct)	M	TLV	4
-
-3.2.2. Register Error
-
-Server -> Client
-
-  IEI	Info Element		Type			Pres.	Format	Length
-	Message type		4.2.1			M	V	1
-  02	Cause			GMM cause,		M	TLV	3
-				04.08: 10.5.5.14
-
-3.2.6. Register Result
-
-Server -> Client
-
-  IEI	Info Element		Type			Pres.	Format	Length
-	Message type		4.2.1			M	V	1
-
-3.2.3. Challenge
-
-Server -> Client
-
-  IEI	Info Element		Type			Pres.	Format	Length
-	Message type		4.2.1			M	V	1
-  20	RAND			octet string (16)	M	TLV	18
-  23	AUTN			octet string (16)	M	TLV	18
-
-3.2.4. Challenge Error
-
-Client -> Server
-
-  IEI	Info Element		Type			Pres.	Format	Length
-	Message type		4.2.1			M	V	1
-  02	Cause			GMM cause,		M	TLV	3
-				04.08: 10.5.5.14
-
-3.2.5. Challenge Result
-
-Client -> Server
-
-  IEI	Info Element		Type			Pres.	Format	Length
-	Message type		4.2.1			M	V	1
-  21	XRES			octet string (8)	M	TLV	10
-
-3.2.3. Sync Request
-
-Client -> Server
-
-  IEI	Info Element		Type			Pres.	Format	Length
-	Message type		4.2.1			M	V	1
-  20	AUTS			octet string (16)	M	TLV	18
-
-3.2.4. Sync Error
-
-Server -> Client
-
-  IEI	Info Element		Type			Pres.	Format	Length
-	Message type		4.2.1			M	V	1
-  02	Cause			GMM cause,		M	TLV	3
-				04.08: 10.5.5.14
-
-4. Information Elements
-
-4.1. General
-
-[...]
-
-4.2.1. Message Type
-
-  +---------------------------------------------------+
-  | 8 7 6 5 4 3 2 1                                   |
-  |                                                   |
-  | 0 0 0 0 0 1 0 0  - Register Request               |
-  | 0 0 0 0 0 1 0 1  - Register Error                 |
-  | 0 0 0 0 0 1 1 0  - Register Result                |
-  |                                                   |
-  | 0 0 0 0 1 0 0 0  - Challenge Request              |
-  | 0 0 0 0 1 0 0 1  - Challenge Error                |
-  | 0 0 0 0 1 0 1 0  - Challenge Result               |
-  |                                                   |
-  | 0 0 0 0 1 1 0 0  - Sync Request                   |
-  | 0 0 0 0 1 1 0 1  - Sync Error (not used)          |
-  | 0 0 0 0 1 1 1 0  - Sync Result (not used)         |
-  |                                                   |
-  +---------------------------------------------------+
-
-4.2.2. IE Identifier (informational)
-
-These are the standard values for the IEI.
-
-  +---------------------------------------------------------+
-  | IEI    Info Element   Type                              |
-  |                                                         |
-  | 0x02   Cause          GMM cause, 04.08: 10.5.5.14       |
-  | 0x20   RAND           octet string                      |
-  | 0x23   AUTN           octet string                      |
-  | 0x24   XRES           octet string                      |
-  | 0x25   AUTS           octet string                      |
-  | 0x30   Client ID      big endian int (2 octets)         |
-  +---------------------------------------------------------+
-
-4.2.3. Client ID
-
-     8      7      6      5      4      3      2      1
-  +-----------------------------------------------------+
-  |     |  Client ID IEI                                | octet 1
-  +-----------------------------------------------------+
-  |   Length of Client ID IE contents (2)               | octet 2
-  +-----------------------------------------------------+
-  |   Client ID number, most significant byte           | octet 3
-  +-----------------------------------------------------+
-  |   Client ID number, least significant byte          | octet 4
-  +-----------------------------------------------------+
-
-The Client ID number shall be interpreted as an unsigned 16bit integer, where 0
-indicates an invalid / unset ID.
-
diff --git a/openbsc/doc/sgsn-remote-protocol.txt b/openbsc/doc/sgsn-remote-protocol.txt
deleted file mode 100644
index 6591d63..0000000
--- a/openbsc/doc/sgsn-remote-protocol.txt
+++ /dev/null
@@ -1,468 +0,0 @@
-
-               GPRS Subscriber Update Protocol
-
-1. General
-
-This document describes the remote protocol that is used by the SGSN to update
-and manage the local subscriber list. The protocol and the messages are
-designed after the corresponding MAP messages (see GSM 09.02) with the
-following differences:
-
-  - The encoding uses TLV structures instead of ASN.1 encodings
-  - Segmentation is not used
-
-See the specification of the Gr interface (GSM 03.60).
-
-2. Connection
-
-The protocol expects that a reliable, ordered, packet boundaries preserving
-connection is used (e.g. IPA over TCP). The remote peer is either a service
-that understands the protocol natively or a wrapper service that maps the
-messages to/from real MAP messages that can be used to directly communicate
-with an HLR.
-
-2.1. Using IPA
-
-By default, the following identifiers should be used:
-  - IPA protocol: 0xee (OSMO)
-  - IPA OSMO protocol extension: 0x05
-
-2. Procedures
-
-2.1. Authentication management
-
-The SGSN sends a SEND_AUTHENTICATION_INFO_REQ message containing the MS's IMSI
-to the peer.  On errors, especially if authentication info is not availabe for
-that IMSI, the peer returns a SEND_AUTHENTICATION_INFO_ERR message.  Otherwise
-the peer returns a SEND_AUTHENTICATION_INFO_RES message. If this message
-contains at least one authentication tuple, the SGSN replaces all tuples that
-are assigned to the subscriber. If the message doesn't contain any tuple the
-SGSN may reject the Attach Request. (see GSM 09.02, 25.5.6)
-
-2.2. Location Updating
-
-The SGSN sends a UPDATE_LOCATION_REQ to the peer. If the request is denied by
-the network, the peer returns an UPDATE_LOCATION_ERR message to the SGSN.
-Otherwise the peer returns an UPDATE_LOCATION_RES message containing all
-information fields that shall be inserted into the subscriber record. If
-the 'PDP info complete' information element is set in the message, the SGSN
-clears existing PDP information fields in the subscriber record first.
-(see GSM 09.02, 19.1.1.8)
-
-[...]
-
-3. Message Format
-
-3.1. General
-
-Every message is based on the following message format
-
-  IEI	Info Element		Type			Pres.	Format	Length
-	Message type		4.2.1			M	V	1
-  01	IMSI			4.2.9			M	TLV	2-10
-
-If a numeric range is indicated in the 'presence' column, multiple information
-elements with the same tag may be used in sequence. The information elements
-shall be sent in the given order. Nevertheless after the generic part the
-receiver shall be able to received them in any order. Unknown IE shall be
-ignored.
-
-3.2.1. Send Authentication Info Request
-
-SGSN -> Network peer
-
-  IEI	Info Element		Type			Pres.	Format	Length
-	Message type		4.2.1			M	V	1
-  01	IMSI			4.2.9			M	TLV	2-10
-
-3.2.2. Send Authentication Info Error
-
-Network peer -> SGSN
-
-  IEI	Info Element		Type			Pres.	Format	Length
-	Message type		4.2.1			M	V	1
-  01	IMSI			4.2.9			M	TLV	2-10
-  02	Cause			GMM cause,		M	TLV	3
-				04.08: 10.5.5.14
-
-3.2.3. Send Authentication Info Response
-
-Network peer -> SGSN
-
-  IEI	Info Element		Type			Pres.	Format	Length
-	Message type		4.2.1			M	V	1
-  01	IMSI			4.2.9			M	TLV	2-10
-  03	Auth tuple		4.2.5			0-5	TLV	36
-
-3.2.4. Update Location Request
-
-SGSN -> Network peer
-
-  IEI	Info Element		Type			Pres.	Format	Length
-	Message type		4.2.1			M	V	1
-  01	IMSI			4.2.9			M	TLV	2-10
-
-3.2.5. Update Location Error
-
-Network peer -> SGSN
-
-  IEI	Info Element		Type			Pres.	Format	Length
-	Message type		4.2.1			M	V	1
-  01	IMSI			4.2.9			M	TLV	2-10
-  02	Cause			GMM cause,		M	TLV	3
-				04.08: 10.5.5.14
-
-3.2.6. Update Location Result
-
-Network peer -> SGSN
-
-  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
-  09	HLR Number		4.2.12			O	TLV	0-9
-  04	PDP info complete	4.2.8			O	TLV	2
-  05	PDP info		4.2.3			1-10	TLV
-
-If the PDP info complete IE is present, the old PDP info list shall be cleared.
-
-3.2.7. Location Cancellation Request
-
-Network peer -> SGSN
-
-  IEI	Info Element		Type			Pres.	Format	Length
-	Message type		4.2.1			M	V	1
-  01	IMSI			4.2.9			M	TLV	2-10
-  06	Cancellation type	4.2.6			M	TLV	3
-
-3.2.8. Location Cancellation Result
-
-SGSN -> Network peer
-
-  IEI	Info Element		Type			Pres.	Format	Length
-	Message type		4.2.1			M	V	1
-  01	IMSI			4.2.9			M	TLV	2-10
-
-3.2.9. Purge MS Request
-
-SGSN -> Network peer
-
-  IEI	Info Element		Type			Pres.	Format	Length
-	Message type		4.2.1			M	V	1
-  01	IMSI			4.2.9			M	TLV	2-10
-  09	HLR Number		4.2.12			M	TLV	0-9
-
-3.2.10. Purge MS Error
-
-Network peer -> SGSN
-
-  IEI	Info Element		Type			Pres.	Format	Length
-	Message type		4.2.1			M	V	1
-  01	IMSI			4.2.9			M	TLV	2-10
-  02	Cause			GMM cause,		M	TLV	3
-				04.08: 10.5.5.14
-
-3.2.11. Purge MS Result
-
-Network peer -> SGSN
-
-  IEI	Info Element		Type			Pres.	Format	Length
-	Message type		4.2.1			M	V	1
-  01	IMSI			4.2.9			M	TLV	2-10
-  07	Freeze P-TMSI		4.2.8			O	TLV	2
-
-3.2.12. Insert Subscriber Data Request
-
-Network peer -> SGSN
-
-  IEI	Info Element		Type			Pres.	Format	Length
-	Message type		4.2.1			M	V	1
-  01	IMSI			4.2.9			M	TLV	2-10
-  04	PDP info complete	4.2.8			O	TLV	2
-  05	PDP info		4.2.3			0-10	TLV
-
-If the PDP info complete IE is present, the old PDP info list shall be cleared.
-
-3.2.13. Insert Subscriber Data Error
-
-SGSN -> Network peer
-
-  IEI	Info Element		Type			Pres.	Format	Length
-	Message type		4.2.1			M	V	1
-  01	IMSI			4.2.9			M	TLV	2-10
-  02	Cause			GMM cause,		M	TLV	3
-				04.08: 10.5.5.14
-
-3.2.14. Insert Subscriber Data Result
-
-SGSN -> Network peer
-
-  IEI	Info Element		Type			Pres.	Format	Length
-	Message type		4.2.1			M	V	1
-  01	IMSI			4.2.9			M	TLV	2-10
-
-3.2.15. Delete Subscriber Data Request
-
-Network peer -> SGSN
-
-  IEI	Info Element		Type			Pres.	Format	Length
-	Message type		4.2.1			M	V	1
-  01	IMSI			4.2.9			M	TLV	2-10
-  10	PDP context id		4.2.3			0-10	TLV
-				(no conditional IE)
-
-3.2.16. Delete Subscriber Data Error
-
-SGSN -> Network peer
-
-  IEI	Info Element		Type			Pres.	Format	Length
-	Message type		4.2.1			M	V	1
-  01	IMSI			4.2.9			M	TLV	2-10
-  02	Cause			GMM cause,		M	TLV	3
-				04.08: 10.5.5.14
-
-3.2.17. Delete Subscriber Data Result
-
-Network peer -> SGSN
-
-  IEI	Info Element		Type			Pres.	Format	Length
-	Message type		4.2.1			M	V	1
-  01	IMSI			4.2.9			M	TLV	2-10
-
-4. Information Elements
-
-4.1. General
-
-[...]
-
-4.2.1. Message Type
-
-  +---------------------------------------------------+
-  | 8 7 6 5 4 3 2 1                                   |
-  |                                                   |
-  | 0 0 0 0 0 1 0 0  - Update Location Request        |
-  | 0 0 0 0 0 1 0 1  - Update Location Error          |
-  | 0 0 0 0 0 1 1 0  - Update Location Result         |
-  |                                                   |
-  | 0 0 0 0 1 0 0 0  - Send Auth Info Request         |
-  | 0 0 0 0 1 0 0 1  - Send Auth Info Error           |
-  | 0 0 0 0 1 0 1 0  - Send Auth Info Result          |
-  |                                                   |
-  | 0 0 0 0 1 1 0 0  - Purge MS Request               |
-  | 0 0 0 0 1 1 0 1  - Purge MS Error                 |
-  | 0 0 0 0 1 1 1 0  - Purge MS Result                |
-  |                                                   |
-  | 0 0 0 1 0 0 0 0  - Insert Subscr. Data Request    |
-  | 0 0 0 1 0 0 0 1  - Insert Subscr. Data Error      |
-  | 0 0 0 1 0 0 1 0  - Insert Subscr. Data Result     |
-  |                                                   |
-  | 0 0 0 1 0 1 0 0  - Delete Subscr. Data Request    |
-  | 0 0 0 1 0 1 0 1  - Delete Subscr. Data Error      |
-  | 0 0 0 1 0 1 1 0  - Delete Subscr. Data Result     |
-  |                                                   |
-  | 0 0 0 1 1 1 0 0  - Location Cancellation Request  |
-  | 0 0 0 1 1 1 0 1  - Location Cancellation Error    |
-  | 0 0 0 1 1 1 1 0  - Location Cancellation Result   |
-  |                                                   |
-  +---------------------------------------------------+
-
-4.2.2. IP Address
-
-The value part is encoded like in the Packet data protocol address IE defined
-in GSM 04.08, 10.5.6.4. PDP type organization must be set to 'IETF allocated
-address'.
-
-4.2.3. PDP Info
-
-This is a container for information elements describing a single PDP.
-
-  IEI	Info Element		Type			Pres.	Format	Length
-	PDP Info IEI					M	V	1
-	Length of PDP Info IE	length, no ext		M	V	1
-  10	PDP context id		big endian int, 1-N 	C	TLV	3
-  11	PDP type		4.2.4			C	TLV	4
-  12	Access point name	04.08, 10.5.6.1		C	TLV	3-102
-  13	Quality of Service	4.2.11			O	TLV	1-20
-
-The conditional IE are mandantory unless mentioned otherwise.
-
-4.2.4. PDP Type
-
-The PDP type value consists of 2 octets that are encoded like octet 4-5 of the
-End User Address defined in GSM 09.60, 7.9.18.
-
-     8      7      6      5      4      3      2      1
-  +-----------------------------------------------------+
-  |     |  PDP type IEI                                 | octet 1
-  +-----------------------------------------------------+
-  |   Length of PDP type IE contents (2)                | octet 2
-  +-----------------------------------------------------+
-  |  Spare                    |   PDP type org.         | octet 3
-  +-----------------------------------------------------+
-  |  PDP type number                                    | octet 4
-  +-----------------------------------------------------+
-
-The spare bits are left undefined. While 09.60 defines them as '1 1 1 1', there
-are MAP traces where these bits are set to '0 0 0 0'. So the receiver shall
-ignore these bits.
-
-Examples:
-
-  IPv4: PDP type org: 1 (IETF), PDP type number: 0x21
-  IPv6: PDP type org: 1 (IETF), PDP type number: 0x57
-
-4.2.5. Auth tuple
-
-This is a container for information elements describing a single authentication
-tuple.
-
-IEI	Info Element		Type			Pres.	Format	Length
-	Auth. Tuple IEI					M	V	1
-	Length of Ath Tuple IE	length, no ext		M	V	1
-20	RAND			octet string (16)	M	TLV	18
-21	SRES			octet string (4)	M	TLV	6
-22	Kc			octet string (8)	M	TLV	10
-
-4.2.6. Cancellation Type
-
-     8      7      6      5      4      3      2      1
-  +-----------------------------------------------------+
-  |     |  Cancellation type IEI                        | octet 1
-  +-----------------------------------------------------+
-  |   Length of Cancellation Type IE contents (1)       | octet 2
-  +-----------------------------------------------------+
-  |   Cancellation type number                          | octet 4
-  +-----------------------------------------------------+
-
-Where the cancellation type number is:
-
-  +---------------------------------------------------+
-  | 8 7 6 5 4 3 2 1                                   |
-  |                                                   |
-  | 0 0 0 0 0 0 0 0  - Update Procedure               |
-  | 0 0 0 0 0 0 0 1  - Subscription Withdraw          |
-  +---------------------------------------------------+
-
-4.2.7. IE Identifier (informational)
-
-These are the standard values for the IEI. See the message definitions for the
-IEI that shall be used for the encoding.
-
-  +---------------------------------------------------------+
-  | IEI    Info Element   Type                              |
-  |                                                         |
-  | 0x01   IMSI           Mobile identity, 04.08: 10.5.1.4  |
-  | 0x02   Cause          GMM cause, 04.08: 10.5.5.14       |
-  | 0x03   Auth tuple     4.2.5                             |
-  | 0x04   PDP info compl 4.2.8                             |
-  | 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  |
-  | 0x09   HLR Number     4.2.12                            |
-  | 0x10   PDP context id big endian int                    |
-  | 0x11   PDP type       4.2.4                             |
-  | 0x12   APN            04.08, 10.5.6.1                   |
-  | 0x13   QoS            4.2.11                            |
-  | 0x20   RAND           octet string                      |
-  | 0x21   SRES           octet string                      |
-  | 0x22   Kc             octet string                      |
-  +---------------------------------------------------------+
-
-
-4.2.8 Empty field
-
-This is used for flags, if and only if this IE is present, the flag is set.
-The semantics depend on the IEI and the context.
-
-     8      7      6      5      4      3      2      1
-  +-----------------------------------------------------+
-  |     |  IEI                                          | octet 1
-  +-----------------------------------------------------+
-  |   Length of IE contents (0)                         | octet 2
-  +-----------------------------------------------------+
-
-4.2.9. IMSI
-
-The IMSI is encoded like in octet 4-N of the Called Party BCD Number defined in GSM 04.08, 10.5.4.7.
-
-     8      7      6      5      4      3      2      1
-  +-----------------------------------------------------+
-  |     |  IMSI IEI                                     | octet 1
-  +-----------------------------------------------------+
-  |  Length of IMSI IE contents                         | octet 2
-  +-----------------------------------------------------+
-  |  Number digit 2           |   Number digit 1        | octet 3
-  +-----------------------------------------------------+
-  |  Number digit 4           |   Number digit 3        | octet 4
-  +-----------------------------------------------------+
-  :                                                     :   :
-  +-----------------------------------------------------+
-  |  see note 1)                                        | octet 2+(N+1)div2
-  +-----------------------------------------------------+
-
-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
-  +-----------------------------------------------------+
-  :                                                     :   :
-  +-----------------------------------------------------+
-
-
-4.2.11 Quality of Service Subscribed Service
-
-This encodes the subscribed QoS of a subscriber. It will be used by the
-SGSN during the PDP Context activation. If the length of the QoS data
-is 3 (three) octets it is assumed that these are octets 3-5 of the TS
-3GPP TS 24.008 Quality of Service Octets. If it is more than three then
-then it is assumed that the first octet is the Allocation/Retention
-Priority and the reset are encoded as octets 3-N of 24.008.
-
-
-     8      7      6      5      4      3      2      1
-  +-----------------------------------------------------+
-  |     |  IEI                                          | octet 1
-  +-----------------------------------------------------+
-  |   Length of IE contents                             | octet 2
-  +-----------------------------------------------------+
-  :                                                     :   :
-  +-----------------------------------------------------+
-
-4.2.12. HLR Number encoded as GSM 09.02 ISDN-AddressString
-
-The HLR Number is encoded as an ISDN-AddressString in GSM 09.02. It
-will be stored by the SGSN can be used by the CDR module to keep a
-record.
-
-     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
-  +-----------------------------------------------------+
-  :                                                     :   :
-  +-----------------------------------------------------+