Chapter 7: Routing and WAN connections LANCOM Reference Manual LCOS 3.50
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Routing and WAN
connections
'address': The network mask is derived from the first bit that is set in
the IP address entered. This and all high-order bits within the network
mask are set. Thus, for example, the address 127.128.128.64 yields
the IP network mask 255.255.255.192.
'class + address': The network mask is formed from the IP address
class and a part attached after the address procedure. Thus, the
above-mentioned address and the network mask 255.255.0.0 yield
the IP network mask 255.128.0.0.
Routers with RIP capabilities dispatch the RIP packets approximately
every 30 seconds.The router is only set up to send and receive RIPs if
it has a unique IP address.The IP RIP module is deselected in the
default setting using the IP address xxx.xxx.xxx.254.
7.2.4 SYN/ACK speedup
The SYN/ACK speedup method is used to accelerate IP data traffic. With SYN/
ACK speedup IP check characters (SYN for synchronization and ACK for
acknowledge) a given preference within the transmission buffer over simple
data packets. This prevents the situation that check characters remain in the
transmission queue for a longer time and the remote station stop sending
data as a result.
The greatest effect occurs with SYN/ACK speedup with fast connections when
data quantities are simultaneously transferred in both directions at high
speed.
The SYN/ACK speedup is activated at the factory.
Switching off in case of problems
Due to the preferred handling of individual packets, the original packet order
is changed. Although TCP/IP does not ensure a certain packet order, problems
may result in a few isolated applications. This only concerns applications that