TCP/IPv6 Configuration and Management Manual (G06.29+, H06.03+, J06.03+)

Maximize the Benefit of the NonStop TCP/IPv6
Architecture
HP NonStop TCP/IPv6 Configuration and Management Manual—524523-012
3-2
Listener Models: How They Benefit From the
NonStop TCP/IPv6 Architecture
Listener Models: How They Benefit From the
NonStop TCP/IPv6 Architecture
Networking applications fall into five listening-model types:

Standard Listening Model

Monolithic Listening Model on page 3-4

Distributor Listening Model on page 3-6

Hybrid Listener Model on page 3-9

Broker Listener Model on page 3-10
This subsection describes these networking application models.
Standard Listening Model
In this method, you have a single process which listens for incoming connections.
When an incoming connection occurs, the listening process spawns a new server
process (which can run in another processor), then passes that server process the
caller's IP address and port number. The spawned process assumes ownership of the
port and does its own socket I/O.
This method allows for parallel instances of the server process. For example, the
common LISTNER spawns instances of FTPSERV. The LISTNER process is the
common point where all incoming connections are handled, but control and data flow is
handed off to separate instances of server processes, which can be distributed across
processors.
As it passes connections to other processors and can use all processors in the system,
the standard listener model provides scalability.
The standard listener model can benefit from the NonStop TCP/IPv6 architecture
because NonStop TCP/IPv6 eliminates the hop that has to occur between the spawned
server process and the processor where the TCP/IP process resides. That hop occurs
on the server process’ first socket call and every subsequent send/receive call. In
NonStop TCP/IPv6, those calls are handled locally, within the server’s processor.
Figure 3-1
on page 3-3 shows a standard listener distributing a connection to a
different processor. Step 3 of the conventional TCP/IP environment (of Figure 3-1 on
page 3-3) shows that FTPSRV must hop to Processor 0 where the TCP/IP process
resides to access the adapter. By contrast, in the NonStop TCP/IPv6 environment, in
Step 3, FTPSRV has direct access to the adapter.