# Table of contents:

• Introduction
• Command information
• Known changes
• Client-server communication example

# Introduction

MSNP2 is the first released version of the Messenger Service Notification Protocol.
It was introduced officially in Client Version 1.0.0863, along with CVR0.

# Command information

It introduces the dispatch service commands:

• INF
• OUT
• USR
• VER
• XFR

It introduces the notification service commands:

• ADD
• BLP
• CHG
• CVR (not in draft, deliberate omission)
• FND (not in draft, deliberate omission)
• FLN
• GTC
• INF
• ILN
• LST
• MSG
• NLN
• OUT
• PNG (not in draft)
• QNG (not in draft)
• REA (not in draft, despite alluding to it)
• REM
• RNG
• SND (not in draft)
• SYN
• URL (not in draft)
• USR
• VER
• XFR

It introduces the switchboard service commands:

• ACK
• ANS
• BYE
• CAL
• IRO
• JOI
• MSG
• NAK
• OUT
• USR

No commands were known to be removed in this version.

# Known changes

(from Beta 2)

• Dispatch Servers now go through the normal logon procedure until USR TrID {method} I (...).
• MD5 now sends the User Handle in I, instead of with the hashed password in S.
• CKI (cookie) authentication now available to Switchboard servers, instead of authenticating with either CTP (default) or MD5.
• Attempting to use CTP to authenticate to Switchboard will now set the password to (null).
• (Other Switchboard changes are known to exist, but have not been researched.)

# Client-server communication example

NOTE: This has been line-broken. Lines beginning with .. followed by a space are continuations of the previous line.

C: VER 1 MSNP2 CVR0
S: VER 1 MSNP2
C: INF 2
S: INF 2 MD5
C: USR 3 MD5 I example@hotmail.com
S: XFR 3 NS 10.0.0.5:1863

Client disconnects from server.

Client opens a connection to 10.0.0.5:1863.

C: VER 4 MSNP2 CVR0
S: VER 4 MSNP2
C: INF 5
S: INF 5 MD5
C: USR 6 MD5 I example@hotmail.com
S: USR 6 MD5 S prefix
C: USR 7 MD5 S $md5(prefix + password)
S: USR 7 OK example@hotmail.com example%40hotmail.com
S: MSG Hotmail Hotmail 95
MIME-Version: 1.0
Content-Type: text/x-msmsgsprofile; charset=UTF-8
LoginTime: 1726321960

C: SYN 8 0
S: SYN 8 1
S: GTC 8 1 A
S: BLP 8 1 AL
S: LST 8 FL 1 0 0
S: LST 8 AL 1 0 0
S: LST 8 BL 1 0 0
S: LST 8 RL 1 0 0
C: CHG 9 NLN
S: CHG 9 NLN
C: CVR 10 0x0409 win 4.10 i386 MSMSGS 1.0.0863
S: CVR 10 1.0.0893 1.0.0893 1.0.0863
.. http://download.microsoft.com/download/msnmessenger/install/1.0/Win98/EN-US/mmssetup.exe
.. http://messenger.msn.com/
C: ADD 11 AL anotheruser@hotmail.com anotheruser%40hotmail.com
S: ADD 11 AL 2 anotheruser@hotmail.com anotheruser%40hotmail.com
C: ADD 12 FL anotheruser@hotmail.com anotheruser%40hotmail.com
S: ADD 12 FL 3 anotheruser@hotmail.com anotheruser%40hotmail.com
S: NLN NLN anotheruser@hotmail.com another%20user
C: REA 13 anotheruser@hotmail.com another%20user
S: REA 13 4 anotheruser@hotmail.com another%20user
C: REA 14 example@hotmail.com example%20user
S: REA 14 5 example@hotmail.com example%20user
S: FLN anotheruser@hotmail.com
C: OUT

Client disconnects from server.
Server disconnects client.