#include <BasicDSCPClassifier.h>

Inheritance diagram for BasicDSCPClassifier:

Public Member Functions
virtual int	getNumQueues ()
virtual int	classifyPacket (cMessage *msg)
Private Member Functions
virtual int	classifyByDSCP (int dscp)

Detailed Description

Just an example for packet classifiers, based on IPv4 DSCP/IPv6 Traffic class. You'll probably need to implement others if your research interest lies in QoS.

Definition at line 29 of file BasicDSCPClassifier.h.

Member Function Documentation

int BasicDSCPClassifier::classifyByDSCP ( int dscp ) [private, virtual]

Definition at line 59 of file BasicDSCPClassifier.cc.

Referenced by classifyPacket().

{
    // DSCP is 6 bits, mask out all others
    dscp = (dscp & 0x3f);

    // DSCP format:
    //    xxxxx0: used by standards; see RFC 2474
    //    xxxxx1: experimental or local use
    // source: Stallings, High-Speed Networks, 2nd Ed, p494

    // all-zero DSCP maps to Best Effort (lowest priority)
    if (dscp==0)
        return BEST_EFFORT;

    // assume Best Effort service for experimental or local DSCP's too
    if (dscp & 1)
        return BEST_EFFORT;

    // from here on, we deal with non-zero standardized DSCP values only
    int upper3bits = (dscp & 0x3c) >> 3;
    //int lower3bits = (dscp & 0x07);  -- we'll ignore this

    // rfc 2474, section 4.2.2: at least two independently forwarded classes of traffic have to be created
    if (upper3bits & 0x04)
        return 0; // highest priority
    else
        return 1; // low priority (best effort)
}

int BasicDSCPClassifier::classifyPacket ( cMessage * msg ) [virtual]

The method should return the priority (the index of subqueue) for the given packet, a value between 0 and getNumQueues()-1 (inclusive).

Implements IQoSClassifier.

Definition at line 35 of file BasicDSCPClassifier.cc.

{
    if (dynamic_cast<IPDatagram *>(msg))
    {
        // IPv4 QoS: map DSCP to queue number
        IPDatagram *datagram = (IPDatagram *)msg;
        int dscp = datagram->getDiffServCodePoint();
        return classifyByDSCP(dscp);
    }
#ifndef WITHOUT_IPv6
    else if (dynamic_cast<IPv6Datagram *>(msg))
    {
        // IPv6 QoS: map Traffic Class to queue number
        IPv6Datagram *datagram = (IPv6Datagram *)msg;
        int dscp = datagram->getTrafficClass();
        return classifyByDSCP(dscp);
    }
#endif
    else
    {
        return BEST_EFFORT; // lowest priority ("best effort")
    }
}

int BasicDSCPClassifier::getNumQueues ( ) [virtual]

Returns the largest value plus one classifyPacket() returns.

Implements IQoSClassifier.

Definition at line 30 of file BasicDSCPClassifier.cc.

{
    return 2;
}

The documentation for this class was generated from the following files:

BasicDSCPClassifier Class Reference

Public Member Functions

Private Member Functions

Detailed Description

Member Function Documentation