Справочник Пользователя для RAD Data comm Modular Access Device with Integrated Router

FCD-IPM Installation and Operation Manual 

Chapter 5  Setup Menu 

 

Routing/Bridging Menu 

5-13 

This option is only available for PPP link protocol. 

Header and 
Control Field 

Compression 

Used for troubleshooting only. Change the Header and Control Field 
Compression setting only if there is a problem with PPP negotiation 

Protocol Field 

Compression 

 

Used for troubleshooting only. Change the Protocol Field Compression 

setting only if there is a problem with PPP negotiation 

IP Compression 

 

Activates Van Jacobson TCP Header Compression on a specified link. 

PPP is often used on slow bandwidth links, such as modems. To make 
the transmission faster, certain parts of the data packets can be 

compressed. 

In Van Jacobson TCP Header Compression the TCP/IP packet header is 
compressed according to RRC 1144. Other protocols running over IP 

(for example, UDP, ICMP) are not affected by using Van Jacobson 

compression. Since PPP is used for point to point transmissions, both 

the local and remote devices must have Van Jacobson TCP Header 
Compression enabled for compression to be performed. To verify that 

Van Jacobson TCP Header Compression is being performed, open the 

Interface Connections Screen 

Multilink 

 

Determines if a line supports multilink PPP (RFC 1990 compliant). 
The line does not support multilink PPP 
The line supports multilink PPP 
The line enables multilink PPP with Bandwidth-on-Demand support 

(for ISDN line only). 
Permitting multilink PPP means that two neighboring links (or two 
ISDN B-channels) will work as a single logical channel, thereby 

increasing the total link bandwidth. If you select Permanent, then both 

links will be connected simultaneously, independent of bandwidth 
utilization. Using BOD permits you to be connected most of the time 

with only one B-channel and to be connected with the second channel 

for small periods of high bandwidth utilization. This method reduces 
connection costs. 
If you choose BOD, then configure the following parameters: 

Sensibility Direction and Sensibility Timeout. 

BOD Sensibility  

Direction 

Defines the traffic direction to be counted in determining whether to 

connect the second line.  

BOD Sensibility  

Timeout 

Defines the time interval for the utilization count