home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
Tech Arsenal 1
/
Tech Arsenal (Arsenal Computer).ISO
/
tek-20
/
tn210.zip
/
NETWORK.EXE
/
NET-4.TXT
< prev
next >
Wrap
Text File
|
1992-07-02
|
3KB
|
45 lines
NET-4.TXT
NETWORK PROTOCOLS
-----------------
The justification for restricting direct user access to the backbone trunk,
and advantages of using a packet repeater on busy user LAN access nodes were
discussed. Thus far we have been addressing improvements that can be made in
a simplex type network environment. Continuing then, let's talk about node
firmware.
Two concepts are to be found in the amateur network. The first is the one
most are familiar with and is based on dynamic routing capability (netrom or
thenet). The advantage of dynamic routing is the network will automatically
update itself when existing nodes go away, or when new nodes are added to the
system. A disadvantage of dynamic routing is that this process adds "overhead"
to the network, or "node barf", as one critic calls it. Node barf is in
reality the node-to-node broadcasts and update exchanges necessary to make the
dynamic process work.
Since all networks have a finite capacity (simplex networks have less than a
finite capacity), this node overhead reduces the amount of user traffic that
can occupy the channel at any given time. Until recently, little attention has
been given to ways of minimizing node barf. However, node overhead can now be
significantly reduced through nodeware selection and intelligent setting of
node parameters.
Another disadvantage of dynamic routing is it has been inconvenient to affect
network control, since earlier versions of network firmware were deficient in
this regard. With the release of TheNet Plus version 2.08, the problems with
inadequate network control and excessive node barf have been addressed.
The second concept is based on a static routing technique and is the one used
with the ROSE network which is also a TNC-2 type of node. Here, network
changes have to be manually entered to a configuration file by either the
NodeOp or someone designated as the network manager. Since destination
routing is "fixed" into each node, there is no node overhead on the system. As
a result, user throughput is improved.
Either concept has advantages and disadvantages. Both work quite well on
lightly loaded simplex networks with the theoretical advantage weighted toward
ROSE on heavier loading. However the bottom line lays not so much with the
type of node firmware concept as it does with RF path design. Swapping out
one type of chip with another on a properly designed network is not likely to
result in a noticeable performance difference.