Internet Draft S. M. Shahrier K. M. Shaheen Document: draft-shahrier-nsis-framework-01.txt InterDigital Expires: December 2002 A Framework for Bi-Directional QoS Signaling Status of this Memo This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC2026. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet- Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsolete by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. Conventions used in this document The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC-2119 [1]. Abstract This Internet Draft describes the end-to-end signaling architecture and framework model for transmitting packets through a series of heterogeneous networks. The Next-Steps-In-Signaling (NSIS) Working Group is already working on defining a set of requirements for the QoS signaling protocol [1]. This document is the follow on to the requirements draft, and the precursor to any solutions document. It outlines a framework for transporting end-to-end QoS parameters, initiated and maintained by the ôOriginatorö of the service. This draft elaborates on the requirements draft. It defines more precisely the scope of NSIS for end-to-end packet flows, in terms of QoS Signaling, where the resource reservations for the service are initiated by the ôOriginatorö end point and whether this service is bi- directional or unidirectional (i.e., receive-only or send-only). The draft is fully backward compatible; it requires no changes to the existing QoS signaling protocols or procedures. It applysapplies Shahrier Standard Track û Expires December 2002 1 A Framework for Bi-Directional QoS Signaling June 2002 generic messages to transport the information needed to establish the desired QoS for traffic flows in either one or both directions. This document can be used as the guideline for a prospective solution to the QoS signaling problem. 1. Introduction With the current evolution toward wireless data, wireless internet, and wireless multimedia applications such as Voice over IP (VoIP), video conferencing, and Video telephony, performance requirements similar to those of existing circuit switched or voice based wireless systems are essential. Among these performance requirements are call setup time, delay, reliability, and Quality of Service (QoS). Ensuring QoS, providing faster call setup time, while reducing the number of QoS control messages across the network, is the subject of this note. This draft introduces the concept of and the architectural framework for bi-directional resource reservation signaling protocol for both Controlled-Load and Guaranteed QoS control services. The existing RSVP signaling allows for uni-directional resource reservations only in the ôsendö direction, while the proposed signaling protocol generalizes the process by allowing simultaneous bi-directional (ôsendö and ôreceiveö) resource reservations on each hop. The proposed signaling protocol is most suitable for applications in which the ôOriginatorö of a service is solely responsible for making the necessary reservations, authentication and their cost. While it is important and necessary to consider QoS from an end-to-end prospective, the NSIS Working Group shall restrict the scope of its activities to the transport and signaling of QoS packets in the NSIS domain only. The objective of this draft is to provide an overview of the architecture and signaling within the NSIS network. 2. Bi-Directional Signaling Protocol Model The underlying assumption is that the ôOriginatorö of a multimedia session negotiates the media information with the ôTerminatedö side. Both sides have to agree on the means by which the session will be carried, including the type of service (audio, video, or/and text), codec information, bit rate for both directions, port numbers, etc. In order to allocate resources for the negotiated session within the NSIS network, the originator of the multimedia session invokes reservation procedures using the proposed bi-directional signaling protocol. The Bi- directional signaling protocol carries the QoS control objects that specify the QoS necessary to carry the traffic in both directions. Shahrier Standard Track - Expires December 2002 2 A Framework for Bi-Directional QoS Signaling June 2002 2.1 Summary of Bi-directional Signaling Protocol The operation of the bi-directional signaling proceeds as follows: 1) The ôOriginatorö provides the QoS parameters describing the nature of the traffic (including the transaction Type; uni- directional or bi-directional). This information is used to construct the various objects of the message format. 2) The ôOriginatorö sends an initial ôSetupö message to the ôTerminatedö end point and waits for a response. 3) The initial ôSetupö message follows a predetermined route to the ôTerminatedö end point where it requests the assignment of resources needed to carry the desired traffic flows. 4) In each hop, the router updates certain fields that indicate whether the requested resources are available and forwards the updated initial ôSetupö message to the next hop. 5) At the ôTerminatedö end point, the updated ôSetupö message is examined. If the resource allocation is satisfactory, a ôTerminatedö end point wishing to complete the transaction replies to the ôSetupö message with an ôAcceptanceö message. 6) The ôAcceptanceö message follows the same path that carried the ôSetupö message from the ôOriginatorö end point. The ôAcceptanceö message carries the final resources that are needed to be installed in the various hops along the signaling route. 7) At each hop ,hop, the ôAcceptanceö message is processed to establish the required resources and then forwarded to the next hop toward the ôOriginatorö end point. 8) At the ôOriginatorö end point, the final ôAcceptanceö message is processed. If successful, the ôOriginatorö end point replies with a ôConfirmationö message back to the ôTerminatedö end point to acknowledge the establishment of the traffic path. 9) During the session, the ôOriginatorö end point is responsible for maintaining the resources. 10)If either side decides to terminate the session, a ôDisconnectö message is sent by the side terminating the resources along the established route. Shahrier Standard Track - Expires December 2002 3 A Framework for Bi-Directional QoS Signaling June 2002 3. Signaling Diagrams This section shows, the signaling diagrams for the Bi-directional signaling protocol. The diagrams show that the proposed protocol is backward compatible with existing QoS signaling protocols. 3.1 Connection Setup (Accepted) Originator IP NETWORK Terminated | | | | | Setup(Type,QoS Param) | Setup(Type,QoS Param) | Setup(Type,QoS Param) | |------------------------>|--------------------- -->|------------------------>| | | | | | | | | | Accept(Type,QoS Param) | Accept(Type,QoS Param) | Accept(Type,QoS Param) | |<------------------------|<------------------------|<------------------------| | | | | | | | | | Confirm | Confirm | Confirm | |------------------------>|------------------------>|------------------------>| | | | | 3.2 Connection Setup (Rejected) Originator IP NETWORK Terminated | | | | | Setup(Type,QoS Param) | Setup(Type,QoS Param) | Setup(Type,QoS Param) | |------------------------>|--------------------- -->|------------------------>| | | | | | | | | | Denied(Type,QoS Param) | Denied(Type,QoS Param) | Denied(Type,QoS Param) | |<------------------------|<------------------------|<------------------------| | | | | | | | | | Confirm | Confirm | Confirm | |------------------------>|------------------------>|------------------------>| | | | | 3.3 Connection Teardown Shahrier Standard Track - Expires December 2002 4 A Framework for Bi-Directional QoS Signaling June 2002 Originator IP NETWORK Terminated | | | | | Disconnect | Disconnect | Disconnect | |------------------------>|------------------------>|------------------------>| | | | | 4. References [1] Brunner, J., "Requirements for QoS Signaling Protocolsö, draft- nsis-req-02.txt (work in progress), may 2002. 5. Contact Information Sharif M. Shahrier InterDigital 781 Third Ave. Phone: 1-610-878-7878 King of Prussia, PA. USA Email: sharif.shahrier@interdigital.com Kamel M. Shaheen InterDigital 781 Third Ave. Phone: 1-610-878-7878 King of Prussia, PA. USA Email: kamel.shaheen@interdigital.com Shahrier Standard Track - Expires December 2002 5