1. Cisco Content Delivery Solutions
Fabrice Serey
Zagreb 23/09/02

2. Agenda
What is CDN ?
Content Switches and their applications in Data Centers.
Caching or how to increase end users response time.
IP Video or how to build a Pay Per View Streaming solution
Conclusion

3. Overcomes Performance Bottlenecks
Origin Server Scalability,
Speed of Light
Peering Point
Congestion
Last Mile
Bandwidth
“Middle Mile”
We know that by bringing applications like e-learning, customer support and ecommerce to the Web, we can begin to solve problems around scaling, cost reductions and availability. But today’s Internet can’t handle the kind of rich content needed to enable these applications.
As we see from this graphic, there are multiple opportunities for congestion points – all the way from the Internet Backbone to the Premises Network.
The “middle mile” problem refers to the peering points within the internet
The “last mile” problem refers to the connection of an enterprise site to the network. These are generally 1 – 3 mb/s AT MOST.
This is a problem – most F500 companies have a less than T1 connection to their branch offices. If you try to deliver a TV-quality broadcast of your CEO, one user will chew up that entire connection.
By bringing content closer to the user – the web page and the rich content it includes – we can overcome bandwidth bottlenecks and open up all kinds of new services at the edge.
T1, DSL,
Cable Modem
Dial-up
Peering Capacity,
ISP Network Capacity
10 Mb to 1 Gb
Ethernet
Gigabit Optical
Network
Cross-Internet
connections
Premises
Network
Internet Backbone
Local Loop

4. CDN definition
“CDNs accelerate the delivery of Web contents by solving access and congestion problems. They open the way to new high-rate service (audiovisual applications, games). After first being only dedicated to Internet, CDNs have now spread to the market of multi-site companies and companies implementing high rate services on their Intranet.”
Major incumbent PTT operator

5. 5 Key Elements of Content Networks
Content Services
Content Delivery
Network Management
Content Switching
Content Routing
Content
Distribution & Delivery

6. Agenda
CDN technical introduction.
Content Switches and their applications in data centers.
Caching or how to increase end users response time.
IP Video or how to build a Pay Per View Streaming solution
Conclusion

7. Traditional Load Balancing : DNS round robin;
PC based load balancers and Layer 4 switches provided rudimentary “load balancing” or “TCP traffic management.” The resulting configurations, however, are content blind and unable to direct Web traffic based on the content being requested. In addition, these configurations are complex, difficult to manage and maintain, and limited in their scalability and performance.
First generation load-balancing solutions provided the intelligence to balance the load between multiple local Web servers, but are limited in the selection process by their inability to analyze web flows based on content type and location. As a result, all content must be mirrored among every server being load balanced. In addition, these devices sit in line on the network creating a single point of failure, and for larger Web sites, a bottleneck in performance.
Layer 4 switches and load balancers, route incoming requests based on the combination of destination IP address, and TCP port. They immediately “bind” a Web browser to a Web server based on the initial TCP SYN request. Therefore the content request is routed before the switch receives the actual HTTP request, making it incapable of optimizing flows based on URL.
This can be problematic in a Web environment. To a Layer 4 load balancer, all Web applications appear to be using TCP port 80 (well-known port for HTTP), making them indistinguishable from one another. Therefore, a CGI request looks no different from a Web-enabled SAP application or streaming audio request, even though all of these requests have very different requirements or may be found on different servers.
Internet
User
Web Server Farm
Load Balancing not mapped to the real load of the server
DNS does not know state of the server
Client interprets differently DNS A record with multiple

8. How Content Services Switching Works
Step 1: User clicks:
Browser talks to DNS for IP Address Browser sends TCP SYN (connect?)
Internet
Step 2: Switch Sends TCP SYN ACK to browser
Step 3: Browser sends URL:
Current Layer 4 switches and load balancers, route incoming requests based on the combination of destination IP address, and TCP port. They immediately “bind” a Web browser to a Web server based on the initial TCP SYN request. Therefore the content request is routed before the switch receives the actual HTTP request, making it incapable of optimizing flows based on URL.
This can be problematic in a Web environment. To a Layer 4 load balancer, all Web applications appear to be using TCP port 80 (well-known port for HTTP), making them indistinguishable from one another. Therefore, a CGI request looks no different from a Web-enabled SAP application or streaming audio request, even though all of these requests have very different requirements or may be found on different servers.
In contrast, Web switches use URLs to route incoming requests to target servers. By looking deep into the HTTP payload, down to the URL and cookie, a Web switch “knows” what content is being requested. This provides unprecedented flexibility in defining policies for security and traffic prioritization – enabling tiered services and ensuring Service Level Agreements are met. Further, the ability to use cookies enables sticky connections – a critical requirement for e-commerce.
There are 5 basic steps involved in web switching:
1. User makes a content request by typing a URL into a browser.
2. Web switch with virtual IP of the requested URL intercepts the request.
3a. Web switch spoofs TCP ACK back to client.
3b. The Web switch examines HTTP header and URL and compares to current content rules to select best server or cache to satisfy the request.
4. A flow is created between the switch and the optimal server and “snaps” together with the flow from the client to the switch.
5. All subsequent packets for that Web flow are forwarded without intervention by the switch controllers.
Step 4: Switch determines Best Server
Step 5: Switch connects to Best Server and splices TCP connection

9. Content Intelligence Defined
Content Services
Switch L4
extended with URL filtering L4
“session”
Switch
Full content switching on:
Host Tag
Entire URL
Dynamic Cookie location
File extension
000’s of rules
000’s of services
00’s of services per content rule
L3 Switch
Session load balancing by IP address and TCP port
Policy based on TCP port
Limited URL filtering on:
Non HTTP GET
HTTP w/ Cookies
File extension
Limited URL visibility
64 strings <=40 bytes
32 rules <= 8 bytes
Switching on MAC address, VLANs
IP Routing
802.1 P/Q policy
The Cisco CSS series is unique in its ability to perform content discovery, the key to achieving content or name-based switching. Content discovery requires: 1) spoofing the TCP using the entire URL and cookie; 2) providing content based keep-alives to detect changes in content; 3) probing the server automatically to determine content attributes then dynamically selecting the best connection for the keep alive.
Conventional load balancers and Layer 4 switches were designed for address-based switching, and differentiate applications based on identity of well-known TCP ports: Port 80 for HTTP and Port 21 for FTP. However, even as more and more information is based on HTTP requests, load balancers cannot differentiate between multiple HTTP requests for different content.
The Cisco CSS series switches were designed for name-based switching and are the only switches to use the entire URL and cookie to select the best site and server.

10. What is being requested?
Why a content switch ?
Platinum Account
Trading
Flash Crowd Insurance
What is being requested?
Who is requesting
it?
Provide redundancy
Location
of best
server?
Real-time
Stock Quotes
media.com
The Cisco CSS series was designed for switching Web flows and is unique in its ability to perform content discovery, the key to achieving content or name-based switching.
Content discovery requires understanding completely what content is being requested by whom and determining the best location to obtain the content. To do this, the Cisco CSS series switches:
use the entire URL and cookie during flow setup to select the best site and server.
provide content based keep-alives to detect changes in content;
probe the server automatically to determine content attributes then dynamically selecting the best connection for the keep alive.
The content intelligence of the Cisco CSS series delivers many benefits:
optimized content delivery, 100% available web sites and content, superior scalability
e-commerce transaction integrity, enhanced site security
ability to offer new services
Investor
Chat Room
Account
Browsing & Customer Service

11. Site & System Security Web site Security
Prevents Denial of Service attacks
Stateful access control
Firewall Load Balancing
Attacker
Internet
The challenge for any successful public Web site is to attract and retain users while eliminating any undesired or malicious traffic. Web site security requirements cannot be fully met using traditional methods. Firewalls, for example, are optimized to prevent access to a network and they do not scale well for today's extremely high-traffic Web environments. This is particularly true for software-based proxy firewall services, which are limited in the number of sessions they support. Each session requires a unique process, placing a heavy processing burden on the CPU, representing a serious performance bottleneck.
FlowWall Security includes Web site security capabilities available in the Cisco CSS series switches. The first tier security services include:
DoS Attack Prevention - Web switches validate every session flow at initial flow setup and eliminate all connection-based DoS attacks and other attempted malicious or abnormal connections with no impact on the performance of the Web switch.
Network Address Translation - Wire speed NAT capabilities on Web switches effectively hide the IP addresses for all devices located behind the Web switch, such as Web servers and caches, eliminating the ability of hackers to attack servers directly by using explicit IP addresses.
Web switches provide firewall services including high speed access control lists that block particular content requests by IP address, TCP port, Host Tag, complete URL, or file type.
For the maximum access control when separate firewall services are required, Cisco CSS series switches can load balance the firewalls.
Firewall Load Balancing - When full firewall security is needed either in the path from the Internet, or to protect mission-critical backend systems or networks, Web switches can prevent bottlenecks and eliminate single points of failure by distributing traffic among multiple load-balanced firewalls.
Secure Services
DMZ

12. Intelligent redirection Cookie sticky Automatic Content Replication
And even more…
Intelligent redirection
Cookie sticky
Automatic Content Replication
Data Centers load balancing
User-tailored Web Services
SSL termination
Box to box redundancy …
On May 17, 2000, Spanish Internet service provider Terra Networks (SA) agreed to pay $12.5 billion in stock for Lycos so it could gain a source of online content. Both Terra and Lycos achieve a significant part of their revenues from online advertising. Their online advertising exploits are based on accurate traffic statistics that they relay to customers and use to favorably influence advertising contracts.
Using the Cisco CSS switch, Lycos is still a “separate entity” from Terra. This allows Lycos to maintain their revenue stream from advertising activities because they can still report accurate traffic statistics…
This is how it works:
1) User makes a request by typing into a browser.
2) Cisco CSS switch intercepts the request.
2a. Switch sends an HTTP redirect to
3) Browser sends
4) Switch finds most suitable server for content request
5) Switch connects to best server
6) Connected
In the scenario above, logs the web page hit like it normally would - without requiring the user to go directly to

13. Cisco 1150X Content Services Switch
40 Gbps Switch Fabric
Up to 6 modules
Up to 80 FE plus 2GE
Up to 12 GE
Redundant AC or DC
CSS 11506
CSS 11503

14. Content Switching Module
High-performance layer 4-7 load balancer of servers, firewalls, caches and more
Single-slot linecard for catalyst 6500
Custom network-processor-based hardware
Full regular expression support (URLs, cookies, HTTP header parsing)

15. Reasons for a data center ?
For operator internal use (ISP services, hosting operator portal, internal services)
To sell new commercial services (with or without VPNs)

16. Data Center ”Layered model”
Internet
Shared
Hosting
Dedicated
Hosting
Co-Location
Streaming
Managed Security
VPN
(FR or ATM PVC, MPLS VPN)

17. Data Center Load Balancing For Internet and Intranet
ISP-1
ISP-2
Content Switch
SSL Content Accelerator
Hosting
Solution Engine
PIX™ Firewall
Web Servers
Content Switch
Database Servers

18. Agenda
CDN technical introduction.
Content Switches and their applications in data centers.
Caching or how to increase end users response time.
IP Video or how to build a Pay Per View Streaming solution
Conclusion

19. How to cache the content ?
PROXY caching
TRANSPARENT caching
REVERSE PROXY caching

20. Proxy Caching Cache Miss Example: Internet Cache 200.200.200.1
Enterprise Network
Internet
Cache
Origin Server
Client
1. Client request to proxy cache 2.
Cache Miss
4. Content request to Origin
Dest. IP:
Dest. Port: 8080
Get: “//
No DNS lookup required by client
In a proxy cache, users request pages from a local cache instead of direct from the source. The local cache gets the page, saves it on disk and forwards it to the user. Subsequent requests from other users of the cache get the saved copy, which is much faster and does not consume Internet bandwidth. In this case the cache acts on behalf of the client.
The example above outlines the operation and characteristics of a proxy cache miss as follows:
1. The client’s browser is configured with the IP address and destination port number of the cache in which it is to send all HTTP requests. Because the client is configured to send all requests to the cache no DNS lookup is required. Instead it becomes the job of the proxy cache to resolve the name only when it does not contain a copy of the requested content. The domain name is included as part of the URL in the HTTP header so that when the cache does not contain the requested content it will use this domain name to resolve the source address for the content.
2. In this example we assume the cache does not contain a copy of the requested content. This is known as a cache miss.
3. The cache performs DNS resolution for the domain name provided as part of the URL.
4. With the name resolved the cache performs a request for a copy of the content from the source.
5. Content is returned from the source to the cache.
6. If the content is cacheable it is stored on the cache for future requests.
7. The requested content is sent to the client.
Notes:
3. DNS resolve of
5. Origin returns content
7. Content sent to client
6. Content stored on cache

21. Transparent Caching Cache Miss Example:
3. Intercepts TCP port 80 traffic and forwards request to cache
Enterprise Network
Internet
1. DNS resolve of
2. Client request to origin
Dest. IP:
Dest. Port: 80
Get: “/training”
Host:
Cache
Origin Server 4.
Cache Miss
In a transparent cache, users request content directly from the source. The request is intercepted and the cache checks to see if it contains a copy of the requested content. If the cache does not contain a copy it gets the page, saves it on disk and forwards it to the user. Subsequent requests from other users get the saved copy, which is much faster and does not consume Internet bandwidth. In this case the cache acts on behalf of the client.
The example above outlines the operation and characteristics of a transparent cache miss as follows:
1. The client’s browser performs a DNS lookup to resolve the IP address of the source for the requested content.
2. With the resolved address the client initiates a TCP session to request content from the source. Note that the client is unaware of the cache. In other words the cache is transparent to the client.
3. The client’s request is intercepted and directed to the cache.
4. In this example we assume a cache miss.
5. Using the IP address resolved by the client the cache performs a request for the content from the source.
6. A copy of the content is returned from the source to the cache.
7. If the content is cacheable it is stored on the cache for future requests.
8. The requested content is sent to the client.
Notes:
5. Content request to Origin
Client
8. Content sent to client
6. Origin returns content
7. Content stored on cache

22. Why caching ? Faster network response time
Decrease traffic load on expensive peering links
Ease traffic monitoring and management (filtering)

23. Internet access for residential customers
BGP peering with
External AS
As#124
As#12
As#317
POP1
POP2
Service Provider
WAN
POP4
POP3
Dial-Up
Cable
ADSL
ETH

24. Faster network response time
ce590#sh stat http perf
Statistics - Performance
Avg Min Max Last
Requests / Second:
Bytes / Second:
Seconds / Request:
Seconds / Hit:
Seconds / Miss:
Cache eliminate this delay
Seconds/Miss depends on peering links to the internet (typically 1-6 seconds)
RT = RTSP + RTinternet + RTwebserver

25. Decrease traffic load on expensive peering links
ce590#show stat http saving
Statistics - Savings
Requests Bytes
Total:
Hits:
Miss:
Savings: % %
Bandwidth saving depends on country and type of users
Typical residential and university saving = 30% - 50%
Business Users, Saving = 20% - 40%

26. Cost Saving Calculation
Monthly savings = Bandwidth (Mbps) x Monthly BW cost/Mbps x Percent HTTP traffic x Byte hit rate
Payback period = purchase price / monthly savings

27. Filtering Web Sense : The best URL database
Out of the box Web Sense server
Smart Filter : The most common tools
Inside the box Smart Filter agent
Smart Filter GUI + License
N2H2

28. Agenda
CDN technical introduction.
Content Switches and their applications in data centers.
Caching or how to increase end users response time.
IP Video or how to build a Pay Per View Streaming Solution
Conclusion

29. Content Delivery Networks Bringing Content Closer to Users
Server Load Balancer and Content Servers
Server Load Balancer and Content Servers
Content
Router
Origin Web Server
Server Load Balancer and Content Servers
Server Load Balancer and Content Servers
Local DNS Server

30. Streaming technology
Live Traffic
Video On Demand
Transparent Caching
and CONTENT
PREPOSITIONING
(E-CDN, I-CDN)
Managed
Streaming
Server*
Stream Splitting
Un-managed
Streaming
Server**
Stream Splitting
Transparent Caching
*Managed streaming server : Owned by the SP in one location
**Un-managed streaming server : Server on the internet

31. Content Engine Streaming capabilities
Full support of RealNetwork functionalities (Proxy, Subscribers, Servers)
Full support of Windows Media functionalities (Native WMS, v4.1)

32. Pay Per View Service
SP are willing to sell more than just Internet access and VPN. Interest in voice and video.
New promising service: Video and Interactive gaming
PPV is ONE possible video service
Video technology is still in its infancy. Microsoft is taking large market share.

33. PPV foundation: Video Streaming
2. Streaming protocol
Video library
VideoServer
IP network
Codec on PC
Content VoD
Content Live
1. Encoding = codec, bit rate, image size, frame per second, key image intervall

34. …with DRM and Billing Encrypted Stream License aquisition Residential
User buy the rights to view a file for a limited amount of time (1 day)
Can not store the file on his PC
Residential
Service Provider
Backbone
Datacenter
300kbit/s streams
900kbit/s streams
VideoServer
Encrypted Stream
Video Library
License aquisition
Broadband access
ADSL, Cable, ETTH
DRM : Digital Right
Mngt Server Unique Per
Content Provider
Billing (Outsourced)

35. Codec: Which quality to expect?
Image quality
Bandwith (Codec)
Access Type
Bad VHS on TV & PC
360kbps
ADSL 512Kbps, Cable* 512kbps ETTH
VHS on TV
700kbps
ADSL 1Mbps, ETTH Corporate Access
DVD on TV
>900kbps
ETTH Corporate Access
DVD on PC
2000kbps
*might have an issue with QoS
Assumption: Video are streamed on TV, not stored and play

36. How can Cisco help ? Residential Service Provider Backbone Datacenter
VideoServer
Video Library
300kbit/s streams
900kbit/s streams
Broadband access
ADSL, Cable, ETTH

37. Agenda
CDN technical introduction.
Content Switches and their applications in data centers.
Caching or how to increase end users response time.
IP Video or how to build a Pay Per View Streaming Solution
Conclusion

38. Content Delivery Networks System Building Blocks
Highly available, scalable, performance network at Layer 2/3
Streaming
Applications
E-Commerce
Web Hosting
Content Delivery Services
Content Delivery Networks
L2/L3 Networks
Intelligent Network Services
Content Distribution
& Management
Content
Routing
Switching
Edge Delivery
Major messages:
Enhance your infrastructure to support next generation content delivery services, DON’T buy products to support any single content delivery application
Cisco has taken a holistic approach to solving the problem, and has defined the 5 key elements of content networking.
By integrating these technologies with your infrastructure, you can leverage the access technologies that you require, AND support a wide range of content netrworking applications now, and in the future.
ONLY CISCO HAS A COMPELTE SOLUTION TO CONTENT DELIVERY NETWORKS
Mobile
Fixed
Wireless
Cable
DSL
Dedicated/
ATM/FR
ISDN/Dial

39. Thank You !!!