Upload
mauricio-arango
View
1.606
Download
1
Embed Size (px)
DESCRIPTION
Citation preview
1
Providing End-to-End Network QoS via Overlay Networks and
Bandwidth On-demand
Mauricio ArangoSun Microsystems
October 2007
2
Internet’s QoS Problem – A result of the Dumb Network Approach • Based on End-to-end principle:
> Advocates minimal core network functions with emphasis on functions at the periphery
> Routing is part of core functions – tightly coupled with packet switching fabric, highly distributed
• Problem - Emphasis on minimal core functions left out key basic features: > Quality of Service (QoS)> Performance Monitoring > Accounting
• A solution - Add needed core functions, “Intelligence”, via Overlay Networks on top of current dumb core
3
Internet’s QoS Problem – A business opportunity• Lack of assured QoS is a business problem
> “Throwing more bandwidth” solution approach isn’t cost-effective
• Rapid traffic growth, specially video, exacerbating problem
• Growing business sectors exploiting opportunity through overlay network approaches> Content Delivery Networks (CDN) - Managed QoS
services > Application Delivery and Wide-area Optimization
Controllers
4
The QoS problem is a routing problem
• Internet’s routing > Doesn’t take into account network performance
conditions > Doesn’t take into account endpoint performance
conditions, such as data center problems • Overlay solution approach
> Why - Changing existing infrastructure is too complex and expensive
> How – hierarchical routing – adding higher-level routing layer that bases decisions on performance data
5
Overlay Networks
• Compensate network weaknesses with computing power: e.g. caching, application-based routing
> An application of Butler Lampson’s principle: "All problems in computer science can be solved by another level of indirection"
6
Overlay Architecture Patterns
• Interception Point – Network element on path of traffic flow, performs packet inspection. Minimally invasive:> Open control points – eg. DNS> Interconnection points – eg. peering points
• Decision Point – Applies rules and executes triggered actions – local or remote
Interception & local decision points
Backbone ISP
Backbone ISP
Backbone ISP Access
ISP
Backbone ISP
Backbone ISP
CustomerNetwork
Internet Backbone
Control & Management OverlayRemoteDecision point
DNSServer
RemoteDecision point
Interception points
Remote Decision Point
7
Telco Overlay – PSTN Intelligent Network
• Most widely adopted PSTN overlay architecture> Goal was to add new telephony services faster and at
lower cost > Making changes in central office and switches was too
complex and expensive• Architecture
> Trigger Points – Interception & local decision points> Service Control Point (SCP) – Remote decision point
8
Session Control Overlay - SIP
InternetBackbone
DNS
SIPProxy
SIP routing overlay
In-network Interception & local decision point
Remote Decision Point
SIPApp Server
ApplicationOverlay
SIPProxy
SIPProxy
Interception & local decision point
9
QoS Overlay – Caching System
DNS
Origin Server
Caching Server
DNSProxy
Internet
CachingManager
QoS Monitoring
1
5
4
3
2
Caching Control Overlay
Remote decision point –Application-level routing
Interception point
7
6
10
DNS
Internet
Load-balancing Overlay – wide-area & local
Data Center B
DNSProxy
Wide & local area load-balancer
QoS Monitoring
Load-balancing Overlay
Remote decision point –Application-level routing
LoadBalancer
Data Center A
Data CenterNetwork
Interception &Decision point
Interception point
11
QoS Routing Overlay – Best wide-area path selection
Pathentry point
switch
DNS
DNSProxy
QoS Monitoring
QoS Routing
QoS Routing Overlay
Data Center
Data CenterNetwork
On-demand connection
Backbone ISP 2
Backbone ISP 1
Traffic Manager
Interception &Decision points
Remote decision point –Application-level routing
Access ISP
12
Systems requirements for Overlay network patterns• Interception and local decision points
> Based on commercial off-the shelf COTS systems with multi-threaded architecture – exploiting parallelism in packet processing
> Packet classification (deep packet inspection) – sophisticated rule-based system – beyond header fields, capable of handling application-level strings> Via packet processing engines – e.g. on top of bare HW (Netra
Data Plane Suite) or new OS functions (Solaris Crossbow)> New APIs manage packet classification rules
• Remote decision points – COTS-based > APIs with interception and local decision points
13
Conclusions & Outlook• Wide range of overlay architectures can be designed with
basic patterns – Simplified approach for design of QoS overlays
• Market for QoS solutions influencing networking trends> Increased use of application-driven routing - Separation from
switching fabric> Increased centralization of routing and other transport control
functions> Increased centralization of performance management and
accounting> Increased use of on-demand bandwidth via connection-oriented
services