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eBusiness Technologies - Value Added Networks
Value Added Network (VAN) - A privately owned network that provides a services for a fees. A Value Added Network usually offers some service or information that is not readily available on public networks. Today's VANs offer a lengthy list of services.
The history of VANs has been tightly coupled with the history of the traditional EDI standards up until recently, so much so that many believed that a VAN was required for EDI, and that VANs could handle only the traditional EDI formats. In fact, this was never true. That common history is described in Implemenation Options - "Traditional" EDI via a VAN.
This page describes today's VANs.
VANs in the Internet Age (the "modern" VAN)
As companies have implemented internet-based communication systems and expanded to multiple internet-enabled trading partners, they have been experiencing first-hand the effort and cost of point-to-point communications which allow trading partners to exchange files directly. Instead of replacing EDI, many companies are now leaving their existing EDI in place. The vast majority of EDI files exchanged between trading partners are currently processed via VANs. Some companies are sending and receiving their X12 or EDIFACT EDI files via the internet. Furthermore, for internet commerce, companies are now "outsourcing" the trading partner internet connectivity to third parties in order to eliminate the effort and cost of point-to-point communications via the internet. Whether or not those third parties call themselves VANs, the service offerings are exactly the same as the traditional service offerings of EDI VANs, and most of the service providers are the same companies that have historically offered EDI VAN services.
Most Vans offer most of these services:
Communications with your VAN are synchronous(2) - your VAN's network must be up and running in order for you to communication with your VAN. However, one benefit of using a VAN is that it allows for asynchronous(2) communications with your trading partners - you can deposit data even if your trading partners and/or their VANs are not on-line at the same time, and your partners can retrieve data even if you are not on-line at the same time. When it comes to support for communication modes, most VANs can support both asynchronous(2) and synchronous(2) data transfer modes, and some VANs still support bisynchronous transfers.
The EDI standards do not specify how EDI data is to be transmitted to a trading partner. Bulk file transfer protocols (e.g., bisynchronous and asynchronous) are used to convey the majority of EDI traffic.
The legacy connections to VANs were leased lines and dial-up. Value Added Network's very high-volume customers typically purchased leased lines (a/k/a dedicated lines) for the network access. In the past, analog lines were used for connection to the VAN's private network but today a T1 or T3 can be used to connect to the VAN's Virtual Private Network. Dial-up direct connection to the VAN is still supported, and various internet connection options can also be used to connect to a VAN. In the legacy solution, to trade electronically, the receiving partner used to be required have a lease-line or dialup to the same VAN as the sender, or a VAN that had an interconnection agreement with the sender's VAN. The "change" is that the receiving partner may have a number of options, including receiving files via the internet, or logging into the VAN's web site and browsing the data online.
Communications Scripts for Connections to VAN's Private Network
Communications Protocols for Traditional EDI
Historically, the high end EDI VANs allow customers to connect to EDI services using many types of protocols such as asynchronous connections, bisynchronous connections (e.g., 2780/3780 Remote Job Entry (IBM mainframe emulation), SNA (e.g., 3770), Organization for Data Exchange through Tele-Transmission in Europe File Transfer Protocol (ODETTE FTP), X.25, X.400 and X.435. Most EDI VANs also provide access using switched and dedicated connections.
Although the scheduled transmission of EDI data is a desirable function, permitting a user to manually start the communications process is also useful. Manual control of the communications software facilitates its initial configuration and aids with correcting communication errors.
Communications Audit Trail
A communications audit trail provides the user with a log detailing the transmission of each interchange. Information typically provided with an audit trail includes: times, dates, identifiers, acknowledgments, errors encountered, etc. Audit trails are useful for debugging transmission problems, generating reports, and verifying that an interchange was sent or received by a trading parter.
Historically, the security requirements have been applied globally, rather than on a file-by-file basis. All files to and from the VAN receive the same level of security. Because VANs handle data for financial institutions and government agencies, what you get with a VAN is the highest possible level of security. It has worked so well for so long that a lot of us forgot it was there. A great deal of the development of internet standards has focused on enabling the same very high level of security.
Flat Addressing - Impact on Registration
While internet addresses, which describe domains hierarchically, are registered on Domain Name Servers (DNS), the VAN-based X12 and EDIFACT protocols use flat addressing. When you send an interchange to a VAN via dial-up to a partner who is on a different VAN, your VAN must do a table lookup to figure out what VAN the receiving party is using. Unlike DNS, the addresses are not automatically distributed to other VANs. If you use only X12 or EDIFACT via dial-up to a VAN (as opposed to using the internet to connect to a VAN or connect directly to a trading partner), your trading partner must contact their VAN and have them add your address and VAN identifier to their lookup table.
VAN services for protocol translation include internet protocols. For example, if you use only dial-up modem protocol, and your partner speaks S-HTTP, you can speak "dial-up modem" with the VAN, who translate it to speak "S-HTTP" with your partner. VANs can also take care of speed conversion so that dissimilar hardware systems can communicate.
Last updated 02 March 2003