Transcript
Next Generation Residential IP Services
-Premium IP Services -
2003. 12. 2
JangwooSon (Netmanias)
son@netmanias.com
www.netmanias.com/ 02-556-9273/016-460-5747
Contents
Where is the Money ?
Telco’s Broadband Access Network
초기의초고속인터넷액세스서비스
Residential
Telco’s Broadband Access Network
Metro Ethernet의도입
Telco’s Stress
Telco (KT, NTT, SBC, Verison, BT, FT, ¡|)
IP Premium Services
How?
Application QoSrequirement
Network QoSRequirement
Network Dimensioning via Application
Service Authentication/Accounting
QoSguarantee
Admission control/Resource Management
QoSProvisioning/QoSEnforcement
QoS/SLA measurement
Triple play Service
VoD
Streaming
server
[1] VoDServices
User Request a VoDMovie
User Request a VoDMovie
Downstream ACL
QoSRequirement: DiffServ(Data Plane)
QoSguarantee: Data Plane (DiffServ)
QoSguarantee: Data Plane (DiffServ)
QoSRequirement: Bandwidth Broker (Control Plane)
Admission Control
인증/과금서버
Admission Control
QoSManager
VoDServer에서Control: Limitations
Congestion !!
BB의도입효과
[2] Video-Phone Service
Upstream QoS
Downstream QoS
Upstream QoSConcern
Upstream QoS(1)
TCP Flow 1-5
TCP Flow 5
Upstream QoS(2)
UDP Flow
TCP Flow 1-5
Video-Phone Service
(1) Packet Edge
(2) Legacy Edge
(1) Packet Edge
(1) Packet Edge
Worst case delay of EF flow with Peak Rate shaping at ingress
12msec
Worst case delay of a packet of a flow belonging to EF Class
< S/R = 1500Bytes/1Mbps = 12msec
Worst case delay of EF flow with Peak Rate shaping at ingress
Video-Phone Service를EF class로처리하고EF Class queue를non-EF Class에비해Static Priority를주는경우, Video-Phone flow가겪는최대지연시간(Worst case delay)는얼마인가?
두가지가정:
(1) EF Class의Application flows는DiffServ망의Ingress Edge에서Peak Rate으로Shaping한다. (CBR source이면상관없고, VBR source이면Equivalent capacity로shaping한다.)
(2) DiffServ망의모든Output link에서, 인가되는EF flows의rate의합보다많은BW가보장된다. 예를들어, 한라우터에EF class flows의rate의합이15Mbps인데EF class가쓸쓸수있는(즉최대로는Physical port BW) BW가10Mbps이면안되고15Mbps 이상이어야한다. 이는BB의도입으로각각의EF flows에대해Admission control을수행해주면보장된다.
위의두가지조건을만족하면한EF flow의DiffServ망에서의Worst case delay는S/R이내로한정된다. 여기서S: Packet size, R: Flows rate (shaped).
그이유는EF flow에속한packet이라우터에도착했을때겪어야하는Delay 요소는i) EF class에속한다른flows의Backlog가있는경우ii) 자기자신의Flows에속한Packet이아직도서비스받지못하고대기하고있는경우iii) Non-EF flow에속한Packet이서비스중일때도착한경우이다.
i)로인해발생하는최대Delay는S/R이며ii)의경우는위의두가지조건이만족되는상황에서는발생하지않는다(앞의그림참조). iii)은발생가능하나Non-EF class flow의Packet size가1500Byte라고하면1Gbps의link에서Serialization delay가12usec이므로과거의저속환경에서와는달리EF flows의품질에영향을주지못한다.
Worst case delay를S/R이하로줄이기위해서는Admission control을통해EF Class의부하량을줄이는것이하나의방법이다. 예를들어앞의그림의예에서EF Class의부하량을25%(SER의Uplink가1Gbps일때Video-Phone Service의최대사용BW를250Mbps로제한)로제한하면Worst case delay를3msec로한정시킬수있다.
Worst case delay of EF flow with Peak Rate shaping at ingress
Flow rate (R)
Packet size (S)
S/R
50% EF
30% EF
384 Kbps
500Byte
10.42msec
5.21msec
3.126msec
1500Byte
31.25msec
15.625 msec
9.375msec
1Mbps
500Byte
4 msec
2msec
1.2 msec
1500Byte
12 msec
6msec
3.6 msec
(2-1) Legacy Edge: Flow Routing
기존의Access Network (ADSLL, VDSLL, Metro Ethernet)을그대로유지하면서QoS를제공할수있는방안을제시
Vendor
Caspian Networks
IP Application
(2-1) Legacy Edge: Flow Routing
Flow Routing Test (1)
Shaping rate of TCP flow {1~5} = 0.343M
0.343M = [4Mbps *{6/(6+8)} ]/5
0.457M = [4Mbps *{8/(6+8)}]/5
Flow Routing Test (2)
TCP Flow 5
TCP Flow 1-5
Flow Routing Test (3)
UDP Flow
TCP Flow 1-5
Flow Routing Test (4)
(2-2) Legacy Edge: NG BRAS
기존의ADSL Access Network를그대로유지하면서Premium Service를제공할수있는방법론을제시
DSLL Forum: TR-59
Vendors
Juniper
Redback
Net.com
Alcatel
Problem Description
PC
TV
(2-2) Legacy Edge: NG BRAS
IP/VC/VP의Hierarchical Queueingand Scheduling을통해ATM Access Network에서QueueingPoint를없앰.
Case Study 1: DSL Forum
Case Study 2: MSF Forum
MSF Technical Report MSF-TR-QoS-001-FINAL
Case Study 3: Alcatel
Case Study 4: Juniper/Redback
5. Harmonics Project
Summary
Future Direction = Premium IP Service
Access Network 구조와Segment에따라다양한방식이제시
Trend ⇒Control Plane (Service Authentication, Admission Control)
+ Data Plane (QoS: DiffServ,…)
