Interactive Media Server Group
The Edge Server
A Proposal for Internet Media Servers
By any measure, the Internet, more specifically the graphical World Wide Web (WWW) is a resounding success. However, that very success may be its undoing. The simple facts are that the amount of WWW subscribers, content providers, and requests by those subscribers for said content grows exponentially faster than the capability of the network to meet the demand and it's quite likely we will never get ahead of this curve. The business and trade press continually preach of its demise, citing lengthy delays and outages, warning of the impending gridlock when the infrastructure totally collapses. This gloomy prediction is based on a profound, new paradigm shift when the text and graphics of today's WWW evolves into tomorrow's world of full motion video and audio. The real-time delivery requirements of video and audio demand a contention-free data channel.
You may ask "haven't technical innovation and
competition always solved issues like this in the past? "
Perhaps, but this particular problem is quite complex:
The Edge Server Solution
Oracle Corporation believes the only solution to this problem is to place the multimedia data repository closer to the consumer of the information. The manifestation of this belief is the 'Edge Server'. The Edge Server caches and/or mirrors multimedia content otherwise stored on the WWW. The principle of the Edge Server could be applied to any web-based information but we should start with video & audio, solve the worst case problems first and then apply the same architectural model to less bandwidth-intensive data types.
In the Edge Server, multimedia data is replicated
at the edge of the WWW, where the user's connection terminates
at the POP. Hyperlinks on web pages become pointers to
streaming media servers that are physically closest to the consumer.
Deployment at the POP
Oracle proposes that an Edge Server gets deployed at each POP. The POP is the physical interface since standard network connections are available such as Ethernet, ATM, and WAN. The POP is the also the logical termination of the user's access point. Packets flowing into or out of the POP are only limited by the access speed of the user's connection. Any data packets that flow behind or through the ISP backchannel (e.g. router) can encounter serious routing delays and contention latency, usually slowing the effective data rate.
By placing the media repository at the POP and behind the router, the user is insulated from the traffic conditions that exist on the Internet at any given time. Network outages and traffic gridlock are held transparent (once data starts streaming from the edge server), so the client device receives the stream as fast as the access connection allows.
Consider a trip to the airport. Your automobile may be capable of traveling much faster than the posted speed limit and it might take 30 minutes to get there. However, if traffic is heavy, the same trip could take 2 hours or more. If you could board a jet from your own neighborhood (without the noise, of course), your trip would be much shorter, more predictable and far less stressful.
Although ISPs do not typically operate large server
farms, they offer co-location of web servers and many are installing
proxy servers that cache most recently accessed URLs. By necessity
they must expand their systems administration capability and add
value or cease to exist in the face of competition (i.e. AT&T
WorldNet, CompuServe, etc.).
Content providers and web publishers can use GUI tools to stage, propagate and update multimedia data to replicated, distributed Edge Server repositories in a mirroring model. An alternative methodology might involve caching algorithms that update edge servers after first user touches a URL. If the requested data was not already cached, a dialog box could inform the user with the approximate time their media would be available, and might suggest they visit other sites in the interim. Either methodology has its strengths and weaknesses.
Push or mirroring tends to increase the likelihood that a URL is stored locally on the Edge Server and does not incur the initial write cost of a caching model, but requires more storage and must be constantly refreshed. Pull or caching models would incur a high cost for the first 'hit', any additional requests would be fulfilled locally and the Edge Server would be more likely to contain the latest update. Oracle believes a combination mirroring/caching hybrid may provide the most flexibility and the ability to manage tradeoffs between performance, storage space, popularity of content and frequent updates.
Once the data is in place, users make requests such
as clicking on hyperlinks and software will broker these requests
to the appropriate Edge Server based on the POP they are connected
to. Only pointer and other control information moves across the
core of the WWW, thus conserving precious Internet bandwidth.
Differential Writeback technology could be utilized to just send
just the updates instead of the entire file, further reducing
network traffic. Logging agents will ensure web publishers and
content providers retain the critical demographic data required
to identify domains, audit trails, etc.
Oracle Corporation is proposing that W3C members
collaborate together and define the most efficient architecture
that will facilitate distributed edge servers on the periphery
of the Internet and explicitly allow:
Response time is slow and getting slower. When content
providers and web publishers roll out streaming, real time multimedia
data in large volumes, the infrastructure of the World Wide Web
will collapse as hundreds of thousands of concurrent streams attempt
to traverse an already clogged Internet. Network upgrades or faster
access cannot be expected to remedy the expected gridlock. Oracle
Corporation proposes the Edge Server; a streaming multimedia server
that is replicated and deployed at the ISP POP on the periphery
of the WWW. Web hyperlinks will point to the Edge Server that
is physically closest to the consumer of the information. Edge
Servers will enable bandwidth-intensive video and audio content
to be played at the fastest possible speed that the user's access
connection can support, insulated from the uncertain conditions
that regularly occur on the web.