Advanced Features |
Using data compression
Compression is a method of reducing the size of data without losing any of the information. Models 412 and 612 of the Netopia ISDN Modem automatically use Stac data compression to compress data to improve data transfer times.
The following check modes are negotiable: None, One Byte Sequence Number, and Extended. The mode is automatically negotiated when a PPP call is placed to another device that supports the compression control protocol. Generally, Extended is the preferred mode. The amount of compression depends on the type of file being transferred. For example, a text file compresses better than a binary (application or executable) file.
Compression is enabled by default. If you enable compression on the ISDN modem and your application uses compression, compression will be disabled in the ISDN modem.
You can use compression in dual B channel Multilink PPP connections and single B channel connections. By using compression on a single B channel, you can achieve performance rivaling a two B channel connection at a fraction of the cost. Because telephone and Internet providers often base charges on the number of B channels used, the Netopia ISDN Modem’s compression feature, which is not available in most other ISDN terminal adapters, lets you achieve nearly the throughput of a two B channel connection at the price of a single B channel connection.
Compression is negotiated between your ISDN modem and the device to which you are placing the Multilink PPP call. To take advantage of data compression, the device you are dialing into must also support data compression. If the other device does not support compression, compression will not be implemented.
