RVP Protocol for Real-Time Presence Information Sonu Aggarwal Lead Program Manager, Exchange Instant Messaging Microsoft Corporation

RVP is a platform for notification applications  Instant Messaging  Instant Messages  between users, distribution lists (“instances” or “classes”)  Online presence tracking  tracking status ( “Online”, “Offline”, etc.) in real time  Distributed Notifications Infrastructure  e.g. pager apps, package tracking

Design requirements  Internet scale  Federated architecture  Organizations want control of their messaging  Meet demanding enterprise requirements  Compatibility with existing proxy and firewall infrastructure  Strong security & access control, even for cross- domain communication  IP addresses cannot be disseminated outside an organization  High performance  Extensible

The federated model ENTERPRISE INTRANETS ISP Clients ISP Server Network Enterprise Server Network Clients Enterprise Server Network Clients Internet users/philc users/scottm microsoft.com acmewidgets.com msn.com

RVP is based on existing standards and efforts  Based on the GENA framework  Strict extension of HTTP/1.1  SUBSCRIBE, UNSUBSCRIBE, NOTIFY, POLL  Adopts the DAV property model  Uses the DAV MKCOL, PROPFIND, PROPPATCH methods  User resources have an “online-status” property, besides others  Users, lists, resources have URIs:  e.g. “ or “ ments/”

Protocol examples: IM and status subscriptions A user subscribes to his “home node” to receive incoming notifications: SUBSCRIBE /users/bruceb/ HTTP/1.1 Host: im.acmewidgets.com From: Man: Notification-Type: update; subtype = Call-Back: Subscription-Lifetime: A user subscribes to another user’s properties, including online status: SUBSCRIBE /users/stevem/ HTTP/1.1 Host: im.microsoft.com From: Man: Notification-Type: update; subtype = Call-Back: Subscription-Lifetime: 86400

Protocol example: set online status PROPPATCH /users/bruceb/ HTTP/1.1 Host: im.acmewidgets.com From: Man: Content-Type: text/xml Content-Length: xxxx <D:propertyupdate> <Z:leased-value> online online offline offline </Z:leased-value> </D:propertyupdate>

Protocol example: instant message notification NOTIFY /users/bruceb/ HTTP/1.1 Host: im.acmewidgets.com From: Man: Notification-Type: update; subtype = Content-Type: text/xml Content-length: xxxx <Z:notification> <Z:notification-to> </Z:notification-to><Z:msgbody> </Z:mime-data></Z:msgbody>

RVP security mechanisms  Every security principal (user, server, etc.) has an X.509v3 Certificate  Connections are SSL-secured (encryption, authentication)  Security can be administered at the method level  e.g. authentication for NOTIFYs but not for UNSUBSCRIBE  Security performance tradeoffs can be made by administrators

RVP is being deployed for a variety of interoperable applications  MS Exchange 6.0 Instant Messaging Server  Clients on a variety of platforms  Preview Beta - Fall ‘98  Instant Messaging Client SDK  ISP custom applications  Wireless device notifications

Status  RVP drafts published  Latest draft at drafts/draft-calsyn-rvp-01.txt  Next draft will reflect implementation  Microsoft is committed to developing an interoperable standard for Instant Messaging through the PIP (“Presence Information Protocol”) effort  Held BOF at last IETF  Asking for WG at August IETF