Integrated Services (IntServ)

IntServ was an attempt by the IETF to add Quality of Service differentiation to the Internet architecture. Components of the Integrated Services architecture include

• A set of predefined service classes with different parameters, in particular Controlled Load and Guaranteed Service
• A ReSerVation Protocol (RSVP) for setting up specific service parameters for a flow
• Mappings to different lower layers such as ATM, Ethernet, or low-speed links.

Concerns with IntServ include its scaling properties when many flow reservations are active in the "core" parts of the network, the difficulties of implementing the necessary signaling and packet treatment functions in high-speed routers, and the lack of policy control and accounting/billing infrastructure to make this worthwhile for operators. While IntServ never became widely implemented beyond intra-enterprise environments, RSVP has found new uses as a signaling protocol for Multi-Protocol Label Switching (MPLS).

As an alternative to IntServ, the IETF later developed the Differentiated Services architecture, which provides simple building blocks that can be composed to similarly granular services.

References

• RSVP and the Internet Integrated Services, P. Pessi, 1997 - http://www.tml.tkk.fi/Opinnot/Tik-110.551/1997/rsvp.html
  A nice presentation of IntServ and RSVP concepts

Integrated Services Architecture

• RFC 1633, Integrated Services in the Internet Architecture: an Overview, R. Braden, D. Clark, S. Shenker, 1994

RSVP

• RFC 2205, Resource <ReSerVation Protocol (RSVP) -- Version 1 Functional Specification, R. Braden, Ed., L. Zhang, S. Berson, S. Herzog, S. Jamin, September 1997
• RFC 2208, Resource ReSerVation Protocol (RSVP) -- Version 1 Applicability Statement Some Guidelines on Deployment, A. Mankin, Ed., F. Baker, B. Braden, S. Bradner, M. O'Dell, A. Romanow, A. Weinrib, L. Zhang, September 1997
• RFC 2209, Resource ReSerVation Protocol (RSVP) -- Version 1 Message Processing Rules, R. Braden, L. Zhang, September 1997
• RFC 2210, The Use of RSVP with IETF Integrated Services, J. Wroclawski, September 1997
• RFC 2211, Specification of the Controlled-Load Network Element Service, J. Wroclawski, September 1997
• RFC 2212, Specification of Guaranteed Quality of Service, S. Shenker, C. Partridge, R. Guerin, September 1997

Lower-Layer Mappings

• RFC 2382, A Framework for Integrated Services and RSVP over ATM, E. Crawley, Ed., L. Berger, S. Berson, F. Baker, M. Borden, J. Krawczyk, August 1998
• RFC 2689, Providing Integrated Services over Low-bitrate Links, C. Bormann, September 1999
• RFC 2816, A Framework for Integrated Services Over Shared and Switched IEEE 802 LAN Technologies, A. Ghanwani, J. Pace, V. Srinivasan, A. Smith, M. Seaman, May 2000

– Main.SimonLeinen - 28 Feb 2006