Operation Manual

Introduction to NetWare MultiProtocol Router for ISDN 3.1 31
to V.42bis, ratios of 4:1 can be achieved, depending on the type of
data transferred. V.42bis works perfectly with ASCII files, but worse
with already compressed files, for example.
In addition to data compression, header compression is imple-
mented for IPX (CIPX) and TCP/IP (van Jacobsen), also downloaded
and processed on the ISDN-Controllers.
Third, the NetWare MultiProtocol Router for ISDN supports packet
sizes of up to 4530 bytes. By joining or splitting packets depending
on their size before transmitting them over ISDN, throughput is
further optimized.
The performance-enhancing features described above could be
regarded at as "toll-saving" features too: the faster data is transferred
over a link, the less time it takes and the less you pay, since ISDN is
charged by the duration of a connection.
♦♦ Bandwidth aggregation
Performance-enhancing features also include both Static Bundling
and Channel On Demand. Static Bundling defines the number B
channels to be set up additionally whenever data is to be transmit-
ted, whereas Channel On Demand only sets up additional B chan-
nels dynamically when the configured load threshold is reached.
With BRIs, up to 8 data channels can be bundled over several ISDN-
Controllers. With PRIs, up to 16 data channels can be bundled.
NetWare MultiProtocol Router for ISDN 3.1 also supports the PPP
Multilink protocol (PPP MP), which was developed by the Internet
Engineering Task Force (IETF) as an extension to PPP. PPP MP
extends PPP so that it can split and combine packets over multiple
parallel links in order to create a higher aggregate data rate. It can be
used to combine the two B channels in an ISDN Basic Rate Interface
line to provide an effective wire speed up to 128 Kbps.
Another method is routing protocol-based load balancing over
parallel links using NLSP; regarding ISDN B channel set-up, this
bandwidth expansion method can be compared with Static Bun-
dling.
AVM is continuously working to enhance products and develope new
products, such as compression and support for Mobile ISDN on the ISDN-
Controller T1, encryption on the ISDN-Controllers B1 and T1, etc. As soon
as future enhancements to the NetWare MultiProtocol Router for ISDN are
available, a release note will be placed on the AVM Data Call Center (see
Note
Introduc.pm6 27.05.97, 21:0331