1. Standardize QoS signaling protocols using Y.1541
Recommendation Y.1541 QoS Classes: A Basis for IP Network QoS Control Neal Seitz, Chair SG 13/WP 4
IP QoS control: key to IP/PSTN network convergence
Y.1541: “Step 1” in achieving QoS enabled IP networks
Quantify user/application needs via standard IP QoS classes
Signal the standardized QoS classes to and among networks
Realize the QoS classes using network QoS mechanisms
Standardize QoS signaling protocols using Y.1541

2. Importance of IP Network QoS Control
VoIP/MM needs are clear, but too demanding for today’s IP
Rec. G “Mouth-to-ear” signal transmission time
Rec. G Categories of speech transmission quality
Rec. G End-user multimedia QoS categories
IP QoS solutions exist, but are not widely implemented
RSVP/intserv -- Controlled load, guaranteed services
DIFFSERV -- EF, AF per hop behaviors (PHBs)
MPLS, MPλS -- Traffic engineering, CoS, QoS, VPNs
Linking user application needs with network QoS mechanisms would advance PSTN/IP convergence

3. Achieving QoS in IP Networks -- Step 1: Quantify User/Application Needs in IP Terms
Relate subjective descriptions of QoS imperfections …
Audio: “staticky, warbley, muffled, clipped”
Video: “blurry, jerky, blocky, busy, blotchy”
With measurable IP network/terminal characteristics …
Packet loss, delay, delay variation, error
Signal compression artifacts, capacity limits
Capture results in a limited set of QoS classes …
Categorize the major IP user application needs
Can be communicated among networks via signaling
Can be implemented with existing IP QoS mechanisms

4. Terminal-to-Terminal QoS
Network QoS
Terminal-to-Terminal QoS
(Y.1541)
 Speed, Accuracy, Dependability
 Service Availability (Future)
Y.1541 “Mapping” Function
 Voice
 Video
 Data
 Call Control
Customer-Perceived QoS
 Subjective Descriptors
 Objective Estimators
Control
Network
Bearer

5. Table 1/Y.1541 -- IP QoS Class Definitions and Network Performance Objectives

6. Table 2/Y.1541 Guidance for IP QoS Classes

7. Attributes of the Y.1541 IP Network QoS Classes
Encompass the major IP user application categories
Are relatable to practical IP network QoS mechanisms
Can be achieved in realistic network implementations
Are verifiable at jurisdictional network boundaries
(TE/IWF can measure QoS to ensure values are met)
Can support QoS negotiation among networks
Meet the need for a lingua franca to support QoS interworking

8. Achieving QoS in IP Networks -- Step 2: Signal QoS Classes to/among Networks
Allow the user requesting service to specify QoS class
Allow specification of traffic descriptor (Rec. Y.1221)
Support requests for basic IP transport: QoS, traffic
Allow well-defined apps to be identified ex(im)plicitly
Let user decide whether to take lower QoS or clear call
Implement dynamic QoS control, not static allocation
Support QoS class mapping among diverse networks
Allow QoS choices for call control, availability (future)
Communicate the Y QoS classes directly

9. Achieving QoS in IP Networks -- Step 3: Realize QoS Classes via Network Mechanisms
A sampling of available QoS control strategies …
Admission control / resource reservation
(IETF: RSVP, RSVP-TE, MPLS CR-LDP, ... )
Priority queuing (IETF: DIFFSERV AF, EF PHBs)
Traffic segregation / routing control
(IETF: MPLS-based VPNs)
Protection switching (SG 13: Rec. Y.1720)
Mechanisms should be activated/controlled by signaling Y.1541 QoS classes among networks

10. IP Network QoS Control: Open Issues and Discussion Topics
IP QoS signaling: requirements, principles, functions
Will networks signal “consumption” of impairment budgets?
Can networks signal commitments to “better” QoS values?
IP network “call” control, availability specifications
QoS interworking among networks ( IP, FR, ATM ...)
IP QoS mechanisms: standardized or proprietary?
Broadcast quality digital video on IP-based networks
Coordinated effort involving several ITU-T SGs, ITU-R, IETF, other stake holders is warranted