Simple Module PPP

File: NetworkInterfaces/PPP/PPP.ned

C++ definition: click here

PPP implementation.

Packets are encapsulated in PPPFrame.

PPP is a complex protocol with strong support for link configuration and maintenance. This model ignores those details, and only performs simple encapsulation/decapsulation and queuing.

In routers, PPP relies on an external queue module (see OutputQueue) to model finite buffer, implement QoS and/or RED, and requests packets from this external queue one-by-one.

In hosts, no such queue is used, so PPP contains an internal queue named txQueue to queue up packets waiting for transmission. Conceptually, txQueue is of infinite size, but for better diagnostics one can specify a hard limit in the txQueueLimit parameter -- if this is exceeded, the simulation stops with an error.

There is no buffering done on received packets -- they are just decapsulated and sent up immediately.

See also: PPPInterface, OutputQueue, PPPFrame

Usage diagram:

The following diagram shows usage relationships between modules, networks and channels. Unresolved module (and channel) types are missing from the diagram. Click here to see the full picture.

Used in compound modules:

If a module type shows up more than once, that means it has been defined in more than one NED file.

PPPInterface

PPP interface. Complements the PPP module with an output queue for QoS and RED support.

PPPInterfaceNoQueue

PPP interface. Assumes inifinite queue.

Parameters:

Name Type Description
txQueueLimit numeric

only used if queueModule==""; zero means infinite

queueModule string

name of external (QoS,RED,etc) queue module

Gates:

Name Direction Description
physIn input
physOut output
netwIn input
netwOut output

Source code:

simple PPP
    parameters:
        txQueueLimit: numeric,  // only used if queueModule==""; zero means infinite
        queueModule: string;    // name of external (QoS,RED,etc) queue module
    gates:
        in: physIn;
        out: physOut;
        in: netwIn;
        out: netwOut;
endsimple