Electronic Commerce, Ecommerce, Network and Internet Payment part 1

Posted by arlene

The worldwide scope of an electronic commerce offer must rely on a set of physical and logical solutions to meet users’ expectations. Not all customers are computer wizards, and the architecture must account for ergonomic factors, in addition to the security of the exchanges and the different methods for accessing the telecommunications network. This section briefly presents the multiple facets of the technologies of electronic commerce, namely, network access and the multiplexing of voice and data as well as information processing, including “back-office” processes.

Network Access

The quality of telecommunications network access is characterized by the link’s capacity (i.e., the bandwidth) in bits per second (bps), the reliability of the network in terms of downtime or time to repair, and the availability of network resources. The physical transmission medium can be copper cables, optical fibers, radio waves,’ or satellite links.

The bit rates depend on the access technology. On the PSTN, modems implementing the ITU-TRecommendation V.90 can achieve bit rates up to 56 kbps (but usually around 45 kbps) in the downstream direction (from the PSTN to the user), while the upstream channel remains at 33.6 kbps. However, DSL (digital subscriber line) twisted pair copper lines can provide much higher bit rates in either one or two directions, depending on whether the technique used is symmetrical or asymmetrical. DSL rates are of particular interest to small- and medium-sized enterprises.

ADSL (asymmetric digital subscriber line) establishes asymmetrical traffic between the two ADSL modems: a downstream channel with a bit rate of 1.5 to 8 Mbps, respectively, at 3.4 and 1.7 miles from the central office, and an upstream channel from 64 to 640 kbps.

Variations of ADSL include RADSL (rate adaptive digital subscriber line) and VDSL (very high bit rate digital subscriber line).

In the case of large enterprises, access can be through ISDN (Integrated Services Digital Network) channels with a bandwidth in multiples of 64 kbps, usually 128 kbps. From the point of view of logical connection and routing, the protocols employed vary from frame relay, ATM, and PPP (Point-to-Point Protocol) to X.25, which is the legacy system in many locations.

Multiplexing of voice and data channels is inextricably tied to complex commercial transactions, especially when the transaction cannot be handled by the standardized tracks of a robot or an “intelligent agent,” such as the negotiation of a trip with several stops, which would require human intervention. Some systems for payment by bank cards are designed to invoke the intervention of a human operator for verification of the transaction when the amount exceeds a specific limit. In such cases, two communication channels are needed, one for the exchange of data (search of a virtual catalog, transmission of card information, etc.) and the other for oral communication.

These connections are readily made when an ISDN connection is available. Unfortunately, the rate of penetration of ISDN is still disappointing; the highest rate, 4.93%, was in Germany, followed by France at 4.75%. The rate in the U.S. was negligible, and in most countries the necessary infrastructure hardly exists.

For analog lines, multiplexing at the customer’s premises is possible using the adaptor defined by ETSI (European Telecommunications Standards Institute) specification ETS 301 141-1 for narrowband multi-service delivery system (NMDS).

In this service configuration, the analog port of the UM (user network interface) is connected to the analog telephone set while the ISDN user port is connected to a computer equipped with an ISDN card. BT (formerly British Telecom) has already commercialized this service in the U.K.

In this case, the first connection between the PC and the Web server for electronic commerce is established through the IP network (connection 1). When the user initiates a vocal contact by clicking on the appropriate key, the Web server contacts the call center via the IP network (connection 2). The call center, in turn, sets up a PSTN call to the user (connection 3). Thus, both the telephone conversation and the Internet connection can progress simultaneously.

The so-called click-and-phone systems with bit rates less than 64 kbps have not met with an enthusiastic user response. One reason is that users must enter a phone number for the commercial agent to call back, which implies that either the user has two distinct PSTN lines, one for Web surfing and the other for the telephone conversation with the operator, or that users would have to disconnect their IP connection and wait for the commercial agent’s call.

The transport of voice traffic in IP packets can improve the service, provided a gateway is placed between the PSTN and the IP network. This model of operation builds on current efforts such as the ETSI TIPHON project to define a standardized interface between voice transported in IP packets and the PSTN. Voice is coded between 6 and 8 kbps and is packetized using the protocol stack RTP/UDP/IP (Real Time Protocol/User Datagram Protocol/Internet Protocol). With this method, there is substantial overhead; to transport a payload of 20 octets (20-ms voice samples at 8 kbps), a 40-octet header will be added. To avoid this drawback, it is possible to add a new protocol layer above the IP layer to compress the header and reduce the overhead to about 2 to 4 octets. While increasing bandwidth usage, the algorithm can produce a burst of lost packets, in case of transmission errors, which undoubtedly will degrade the quality of the transmitted voice. This degradation is particularly noticeable if, to reduce cost, most of the trajectory is on the IP network and the separation of the joint flow into its constituents is as close as possible to the destination.

To avoid these problems, the joint flow can be limited to the local loop between the user PC and the router of the Internet service provider. After that point, the traffic will be separated and routed differently: voice on the PSTN or the ISDN, and data on the IP network. The router can be managed by the Internet service provider (Case I), the telephone operator (Case II) or a value-added network (Case III).

In the first case, the gateway sets up the telephone call in lieu of the user. The second configuration requires that the gateway send signaling messages conforming to the signaling system no. 7 (SS7) protocol to exploit the intelligence of the public switched network. Finally, if the gateway is in a third-party network, tight coordination is needed to ensure a smooth integration of the various networks.

Possibly related posts: (automatically generated)
Electronic Commerce, Ecommerce, Network and Internet Payment part 1

• Ecommerce revolution, Online Marketing
• Electronic Commerce Payment Concern
• Web Technology & Ecommerce Online Solutions
• Email Marketing
• A New Kind of "Shelf"
• Is the Future of Ecommerce Mobile?
• New Rules of Engagement
• Standardization of electronic commerce
• Ten Essential E-merchandising Techniques
• Which means of payment?