Title: HTTPNG and ClientAgentServer Networking A MobileWireless Perspective
1HTTP-NG andClient-Agent-ServerNetworkingA
Mobile/Wireless Perspective
- Author
- Spencer Dawkins - Nortel (Northern Telecom)
- sdawkins_at_nortel.com
2Client-Agent-Server Networking
- Mobile Network Computer Reference Specification
Data Networking Team - A snapshot of Work-in-Progress
- Mobile Network Computing Protocol (MNCP)
- Wireless Application Protocol (WAP)
- Mobile Office Workstations using GSM Links
(Mowgli) - Moving Rapidly, in MNCRS and IETF
- Combined MNCRS proposal expected within days
- TCP Performance-Enhancing Proxies in IETF
3Low-end Device Challenges
- Categories
- Professional Assistant Devices
- Information Access Devices
- Messaging, Paging, and Telephony Devices
- Limits on everything
- Memory (4 MB RAM 4 MB ROM is common)
- Screen Size and Color Capabilities
- Input Devices
- Network Capabilities and Bandwidth
- HTTP-NG as part of the puzzle
- Taking a systems view of HTTP-NG
4Todays HTTP Protocol Stacks
WWW Server
WWW Client
HTTP Caching Proxy
HTML
HTML
HTTP
HTTP Relay
HTTP
TCP
TCP
TCP
TCP
IP
IP
IP
IP
Standard Protocols
5What Breaks for MNCRS Devices
- HTML
- Perception of HTML as complex
- HTTP
- Perception of HTTP as complex
- Managing appropriate content variants
- TCP
- Perception of TCP as complex
- Slow-start and Slow-restart interactions
- IP
- Perception of IP as redundant on wireless links
These are widespread perceptions!
6MNCP at 50,000 feet
WWW Server
MNCP-specific Client
MNCP-specific Relay
HTML
HTML
HTTP
HTTP Relay
HTTP
TCP
TCP
MNCP/UDP
MNCP/UDP
IP
IP
CDPD
CDPD
MNCP-specific Protocols
Standard Protocols
7Mowgli at 50,000 feet
WWW Server
Mowgli-specific Client
Mowgli-specific Relay
HTML
HTML
HTTP
Mowgli Proxy
Mowgli Agent
TCP
TCP
Mowgli Data Channel Service
Mowgli Data Channel Service
IP
IP
Mowgli-specific Protocols
Standard Protocols
8WAP at 50,000 feet
WAP-specific Server
WAP-specific Client
WML
WML
WSP
WSP
WAP-specific Relay
WTP-C
WTP-C Relay
WTP-C
USSD
IP
IP
USSD
WAP-specific Protocols
Standard Protocols
9The Doomsday Scenario
WWW Client
Double-Duty Server
Not-WWW Client
HTML
Not-HTML
HTML
Not-HTML
HTTP
HTTP
Not-HTTP
Not-HTTP
TCP
TCP
Not-TCP
Not-TCP
IP
IP
Not-IP
Not-IP
Different Standard Protocols
Standard Protocols
10The Doomsday Scenario - Lowend Devices
WWW Server
Double-Duty Client
Not-WWW Agent
HTML
Not-HTML
HTML
Not-HTML
HTTP
HTTP
Not-HTTP
Not-HTTP
TCP
TCP
Not-TCP
Not-TCP
IP
IP
Not-IP
Not-IP
Different Standard Protocols
Standard Protocols
11What might/should Agents do?
- Todays Proxy/Firewall functionality
- Access control, caching
- Transforming Content
- Scale content for small displays, compress HTML
- Transforming HTTP
- Binary Encoding
- Transforming TCP
- Preserving, or not preserving, TCP semantics
- Transforming IP
- Network Address/Port Translation
- IPSec transport termination
12Suggested Principles
- Change as little as possible
- My suggestions - content, TCP
- Minimize duplication of functionality
- Change things at the edge of the network
- Do not require Internet-wide changes
- Change things that make sense for everyone
- Content Negotiation
- Markup language compression
- Keep IP as the protocol stack wasp-waist
- IP Addressing
- IP Security
13References
- MNCP
- lthttp//www.ietf.cnri.reston.va.us/internet-drafts
/draft-piscitello-mncp-00.txtgt - WAP
- lthttp//www.wapforum.org/docs/WAPArch-Sep-97.pdfgt
- Mowgli
- lthttp//www.cs.helsinki.fi/research/mowgli/arch/mo
wgli-arch.htmlgt - MNCRS
- lthttp//www.mncrs.org/gt, and specifically
- lthttp//www.oadg.or.jp/activity/mncrs/mobcomm/modl
tabl/network-model-feb98.htmlgt