1. Network Services
Geoff HUSTON

2. IP Access is not enough An ISP service also requires:
mail & mailing lists
DNS
web
usenet
ftp
...

3. Mail Services Outbound Mail Server Mail Server Secondary Mail Client
Mail Alias
Local Access
Account
Secondary
Inbound Mail delivery
Backup
Mail
Client
POP or IMAP Access
to Mail Account
Outgoing Mail server
Outbound Mail
Server

4. Mail Services Customer mailboxes SMTP server POP / IMAP access server
account management
alias management

5. Mail Services SMTP relay for outbound mail Secondary MX for customers
Mail List management for customers

6. DNS Services Hosting Primary Domain Service Secondary DNS Server
DNS Forwarder

7. Web Caching improved fetch performance ISP cost reduction
virtual web servers (virtual domains)
proxy servers
accepting advertisements on the web page

8. Caching
GET
cache 1 2

9. Large Scale Caching Core Cache System cache client
ISP Network
cache server
client
cache
ICP requests
Core Cache System

10. POP Cache Architecture
Core
Network to
customer
sites
Access Servers
LAN Switches
Servers
Core Router
Cache
Redirect TCP port 80 requests
to local cache system

11. Web Hosting Virtual web hosts http://www.net.isp
sub 11
sub 121
sub 12
sub 1
sub 2
sub 31
sub 321
sub 322
sub 32
sub 33
sub 3
sub 4
user page

12. USENET servers can be a valuable service can be expensive!
too much traffic getting-in
too much hard disk capacity
maintenance cost a lot!

13. Games and Entertainment
The Internet is not intended to be serious and there’s a perfectly good market for games and entertainment
Game servers
Streaming audio/video servers …

14. Upstream ISP Upstream Feed Router Local Office Access Router
Network Access
Server
Access
Filters
Radius
Mail
DNS
WWW
Cache
Usenet
Accounting
Data
Network
Management

15. Dial-Up Network Access Server Network Client Access Router
45Mbps Backbone
Radius
Server
Mail
DNS
WWW
Cache
Usenet
Accounting
Data
Network
Mgmt
Dial-Up Network
Access Server
Network Client
Access Router
Backbone Router

16. Dial-Up Network Access Servers Network Client Access Routers
622MbpsSONET Backbone
Dial-Up Network
Access Servers
Network Client
Access Routers
Backbone Router
Add Drop Mux
Fast Ethernet Switch
Radius
Server
Mail
DNS
WWW
Cache
Usenet
Accounting
Data
Network
Mgmt
155Mbps Fiber Connectors

17. Adding Security to the Design
Network
Router
Local Office
Access Router
Network Access
Server
Radius
Mail
DNS
WWW
Cache
Usenet
Accounting
Data
Management
Service Plane
Control and Management Plane

18. Example: Securing the Usenet Server
Network
Management
Server
Upstream Feed Router
Local Office
Access Router
Network Access
Radius
Mail
DNS
WWW
Cache
Usenet
Accounting
Network Carriage Plane
TCP logging
SYN protection
permit any source connect to TCP port 119
permit NetOpsCenter source to any port
deny all else
no loose source routing
no directed broadcast
permit any source to usenet server TCP port 119
permit NetOpsCenter source to usenet server
ISP Service Plane
Example: Securing the Usenet Server
ISP Management Plane

19. Service Issues Do ISP services attract a different tariff?
How are service ports accounted?