1Peer to Peer Networking

                                                                
                by Richard Hawes



The first networks were typically created to share expensive
resources such as a mainframe computer or large, complex
printers. Often the workstations that connected to the mainframe
through the network were of limited capabilities, so the
mainframe performed the majority of the work.  



However, the functionality of networking, coupled with the
enormous increase in workstation capability allowed users to
connect together in a network and  do far more than just work
with data and programs on a mainframe. Modern networking
products now enable individuals to make data available and share
it with others in their peer group. Providing data to the
corporate network has become almost an ancillary role for the
network.  OS/2 Warp Connect includes IBM Peer for OS/2 because
peer to peer computing is now an essential means of network
communications. 



A computing dictionary will define Peer to Peer Networking as
the interaction between two workstations without the need for a
'controlling' host. In the PC arena, this means sharing some
form of resource between two computers without the need for some
Server system to initiate the links. Peer Networking has given
rise to Workgroup computing - PCs connected to one another share
data in common applications and users can work together sharing
information to complete a project or perform a group-related
task. Peer functions often operate hand-in-hand with workgroup
applications.



Peer Networking allows groups to get PCs connected and working
together on shared data quickly, with little effort. It involves
installing some network hardware and software on each
workstation. The hardware, such as Token Ring, Ethernet,
wireless LAN and others will  connect the systems together. The
software will generally provide at least two capabilities. The
first capability enables a workstation to operate as a Peer
Server. The peer software makes resources from the "server" PC
available to the rest of the workstations on the LAN. In IBM
OS/2 peer products, these resources include file resources such
as hard disks and  CD ROM drives, as well as printer queues and
communications ports.  The benefit of this capability is that
many PCs on a LAN can share one resource such as a printer and
therefore peer products reduce the number of resources needed to
be bought and maintained.  



The second capability enables a workstation to operate as a
client. The client function allows a user to initiate a
connection with a Peer Server and attach to any of the server's
resources. The user at a client PC will have a 'redirector'
component that makes the remote resource look and behave as if
they were local to the client. This means that the client will
see a file resource as it does any other disk drive it has. The
remote disk drive will have a drive letter and will be visible
from applications that check for drives, including GUI features
as in the OS/2 Workplace Shell Drives object. The same will
apply for the printer and communications port connections. The
client PC will use an LPT or communications port (and in OS/2
can use a desktop printer object) which will behave as if the
port were locally available on the client, yet the printer or
modem might be attached to any machine in the network that is
accessible as a Peer server. (Note that most DOS peer products
do not allow the redirection of the communications ports).



Access to the resources of the Peer server can be controlled.
For example, users can be required to logon to a Peer Server
with a user ID and password. In addition it is possible to
restrict reading or writing access privileges.



As companies and their networks grow, the better peer products
can be integrated with the corporate network. This may start
with taking a Peer Server and sharing its resources across the
whole network and progress to allowing users to continue to
access other resources around the network (such as mainframe and
mid-range systems peripherals), in the same, seamless way as the
peer resources are accessed.



IBM's peer functionality in OS/2 Warp Connect is based on the
industry standard NetBIOS and Server Message Block protocols
used in many other networking, workgroup and peer products. This
allows OS/2 Warp Connect to communicate with and provide
services to clients from various products, examples include
Microsoft Windows for Workgroups, LAN Manager and Windows NT and
IBM LAN Server and DOS LAN Requesters.