Application of RMTP: distributing marketing information

Deliverying up-to-date information to the marketing front

For a company that has a large number of branch stores or a large number of salesman, deliverying product information, price lists, promotion program information and marketing strategies to the clerks and the salemen in time is a serious problem. RMTP enables reliable, simultaneous, and short time delivery to a large number of terminals by using multicast technology.

Recently, a number of information distribution mechanisms such as WWW (World Wide Web) in the name of "Intranet" and Groupware (Lotus Notes, as an example) have been used for delivering such marketing information to the sales front. The information stored in the central server is accessed via "browsers" in the case of Web, and via Notes clients in the case of Notes-based groupware system.

Let us suppose the price list is updated. In the next morning the 10,000 terminals at branch sales offices accesse the updated price list just after the stores open. Customers are waiting at every window, and the sales clerk is irritated with the slow response of the terminal if the server and network capacities are sufficiently large. The network is used to transfer the same price list data as many as 10,000 times in a very inefficient way.

To improve this situation, we can design a network with data caching servers at every regional center. The "proxy cache server" mechanism in Web system and the database replication mechanism in groupware will be used for this purpose. These mechanisms will save the traffic problem, but introduce problems in managing the system. First, we need to pay for the cost of the cache/replication servers whose CPU and disks are rather expensive. Moreover, we need to install and manage the application software packages such as Web cache server and groupware server. Second, we always need to worry about data consistency/integrity between the replicas and the original data, especially when an accident occurs. The access from the terminals to the intermediate caching servers, and the caching servers to the main server are still one to N, while N is significantly less than the number of clients, and the situation that identical data is sent many times and many accesses causes response delay does not change at all.

RMTP solves this problem. RMTP distributes data by the multicast capability of the network, where the data packets are copied at the switching/branching nodes (routers) within the network. Only the necessary number of copies are made at the branching nodes only when necessary. The information server transmits out only one copy to the network. So, both the server and the network link to the server can be small to accomodate only one copy of the packet. On the other hand, the time to transmit the data is the same as sending to one terminal just as the parallel transmission, and the delivery to a large number of terminals (5,000 to 10,000) can be completed in a few minutes. RMTP solves this problem.

Native multicast is effective in reducing server size and network traffic, but lacks reliability in data delivery. As the multicast transfers data to all the designated terminals simultaneously, it does not worry about lost messages even if a part of network experiences delivery problem but continues transmission. As a result, a portion of the data remains undelivered to the terminals connected to the troubled network part. This is exactly the same as the fact that in the TV broadcasting, if a problem occurs in the radio propagation condition and some picture frames are damaged, the TV transmission progresses leaving the lost frames without any care. RMTP realizes reliability of delivery to all the terminals even with such an unreliable multicast transmission mechanism.Moreover, RMTP notifies to the server the fact that the data can not be sent to the client, if the link to it remains dead or any other reason. This notification allows the electronic newspaper application to avoid charging the particular copy to the undeliverable subscriber's account.A more good news is that RMTP Version 1 is extended to Version 2 to cover mobile communication, while the merits of reliable multicast are sustained. This enables salesmen who work outside their offices can enjoi the reliable delivery in a short time offered by RMTP. For example, if you prepare a mobile terminal accessible from the server via a packet radio link or a cellular link, the data in the terminal is updated by the center server simultaneously, and you will have the up-to-date product information at hand, even outside your office.