# Table of contents:

• Introduction
• Client/Request
• Server/Response
• Examples
  • Inviting a user successfully
  • User already invited
  • User to invite was invalid
  • User is offline
  • That user does not allow you to contact them
  • You are being rate limited
  • Invalid context (Notification Server)
• Known changes

# Introduction

CAL is a command introduced with MSNP2.

It is a Switchboard Server command, without either a request or response payload.

It invites ("calls") a user to a Switchboard session.

# Client/Request

CAL TrID user-handle

Where user-handle is the user that you'd like to invite.

# Server/Response

CAL TrID RINGING session-id

Where RINGING is always RINGING, as there are no other states avaliable.

Where session-id is the Switchboard session identification number.

# Examples

# Inviting a user successfully

C: CAL 1 anotheruser@hotmail.com
S: CAL 1 RINGING 987654321

# User already invited

C: CAL 2 anotheruser@hotmail.com
S: 215 2

# User to invite was invalid

C: CAL 3 hello
S: 208 3

# User is offline

C: CAL 4 anotheruser@hotmail.com
S: 217 4

# That user does not allow you to contact them

All instances that returned this have been changed to a 217. This response is obsolete.

C: CAL 5 anotheruser@hotmail.com
S: 216 5

# You are being rate limited

C: CAL 6 anotheruser@hotmail.com
S: 217 6
C: CAL 7 anotheruser@hotmail.com
S: 217 7
C: CAL 8 anotheruser@hotmail.com
S: 217 8
C: CAL 9 anotheruser@hotmail.com
S: 217 9
C: CAL 10 anotheruser@hotmail.com
S: 217 10
C: CAL 11 anotheruser@hotmail.com
S: 713 11

# Invalid context (Notification Server)

Inherited from being an unimplemented command.

C: CAL 12 anotheruser@hotmail.com

Server disconnects client.

# Known changes

None.