The Basic principle and Configuration of a Virtual Leased Line (VLL) Community

A Digital Leased Line (VLL) company is a issue-to-position knowledge conversation utilizing ADSL network (above ATM) for communicating any info concerning two internet sites. The data pace of VLL depends on client prerequisites these kinds of as 64, 128, 256, 512 Kbps.

In real community, several end users are linked to DSLAM also, the assistance company assigns the VLL ratio for bandwidth sharing, when every buyer sends knowledge simultaneously. This is a drawback of VLL service when in contrast with Leased line (LL) company. For the latter provider, it can use a complete bandwidth which is not shared with other prospects. The benefit of a VLL services is that it is much less expensive than a LL company.

The essential VLL configuration is demonstrated in the diagram beneath.

Personal computer-A –> ADSL Router-A –> DSLAM-A –> ATM Change-A —>ATM-Switch-B –> DSLAM-B –> ADSL Router-B –> Laptop-B

From this diagram, the VLL configuration is divided into two web pages : the company site and the customer website. In the company service provider, there are two DSLAMs (Digital Subscriber Line Obtain Multiplexer) and two ATM switches for transmitting and acquiring any knowledge site visitors between two consumer internet sites. DSLAM is used for combining facts signal from numerous prospects and then sends data to ATM change. Following obtaining details from DSLAM, ATM swap searches the best route instantly to the other web site by only configuring VPI / VCI parameters at the DSLAM link and ATM switch link. At DSLAM’s vacation spot side (closing to ATM-SW), the VPI / VCI of DSLAM-A need to be the exact same as ATM SW-A’s, and the VPI/VCI of DSLAM-B should be the same as ATM SW-B’s.

In every single purchaser web page, there are an ADSL Router and perform stations (a server, a Personal computer, or other LAN devices). Prospects ought to configure their ADSL routers in VLL mode by placing the relationship sort to “RFC1483 Route”. At DSLAM’s supply aspect (closing to ADSL Router), the VPI / VCI of DSLAM-A will have to be the same as ADSL Router-A’s, and the VPI/VCI of DSLAM-B should be the identical as ADSL Router-B’s. These parameter values rely on just about every telecommunication provider’s assignment.