net.sourceforge.jsdp
Class Bandwith

java.lang.Object
  net.sourceforge.jsdp.Bandwith

All Implemented Interfaces:

Serializable, Cloneable, Field

public class Bandwith
extends Object
implements Field

A Bandwith represents an b=<field value> field contained in a SDP message.

A bandwith field specifies the proposed bandwidth to be used by the session or media, and is optional. Multiple bandwidth specifiers of different types may be associated with the same SessionDescription. Each has the form b=<modifier>:<value>. There are four bandwith modifers (or types):

• AS: Application Specific maximum. The bandwidth is interpreted to be application-specific, and will be treated as application's concept of maximum bandwidth


• CT: Conference Total. An implicit maximum bandwidth is associated with each TTL on the Mbone or within a particular multicast administrative scope region (the Mbone bandwidth vs. TTL limits are given in the MBone FAQ). If the bandwidth of a session or media in a session is different from the bandwidth implicit from the scope, a b=CT:<bandwith> line should be supplied for the session giving the proposed upper limit to the bandwidth used.
  The primary purpose of this is to give an approximate idea as to whether two or more conferences can co-exist simultaneously


• RS: RCTP bandwith for data senders


• RR: RCTP bandwith for other participants in the RTP session

Since:

0.1.0

Version:

1.0

Author:

Claudio Di Vita

See Also:

Serialized Form

Field Summary

static String	AS The AS modifier
static String	CT The CT modifier
protected String	modifier The bandwith modifier
static String	RR The RR modifier
static String	RS The RS modifier
protected int	value The bandwith value, in kbits/second

Fields inherited from interface net.sourceforge.jsdp.Field

ATTRIBUTE_FIELD, BANDWITH_FIELD, CONNECTION_FIELD, EMAIL_FIELD, END_OF_FIELD, INFORMATION_FIELD, KEY_FIELD, MEDIA_FIELD, ORIGIN_FIELD, PHONE_FIELD, REPEAT_TIME_FIELD, SESSION_NAME_FIELD, TIME_FIELD, TIMEZONE_FIELD, URI_FIELD, VERSION_FIELD

Constructor Summary

protected	Bandwith() Creates a new Bandwith.
	Bandwith(String modifier, int value) Creates a new Bandwith.

Method Summary

Object	clone() Returns a clone of this field.
String	getModifier() Returns the bandwith modifier.
char	getType() Returns the type character for the field.
int	getValue() Returns the bandwith value.
static Bandwith	parse(String field) Parse an input string and constructs the equivalent bandwith field.
void	setModifier(String modifier) Sets the bandwith modifier.
void	setValue(int value) Sets the bandwith value.
String	toString() Returns a string representation of the field.

Methods inherited from class java.lang.Object

equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

AS

public static final String AS

The AS modifier

See Also:

Constant Field Values

CT

public static final String CT

The CT modifier

See Also:

Constant Field Values

RS

public static final String RS

The RS modifier

See Also:

Constant Field Values

RR

public static final String RR

The RR modifier

See Also:

Constant Field Values

modifier

protected String modifier

The bandwith modifier

value

protected int value

The bandwith value, in kbits/second

Constructor Detail

Bandwith

protected Bandwith()

Creates a new Bandwith.

Bandwith

public Bandwith(String modifier,
                int value)
         throws SDPException

Creates a new Bandwith.

Parameters:

modifier - the bandwith modifier

value - the bandwith value in kbits/second

Throws:

SDPException - if the modifier is unknown, or the value is negative

Method Detail

parse

public static Bandwith parse(String field)
                      throws SDPParseException

Parse an input string and constructs the equivalent bandwith field.

Parameters:

field - the string to parse

Returns:

a new Bandwith instance

Throws:

SDPParseException - if an error occurs while parsing

clone

public Object clone()

Returns a clone of this field.

Specified by:

clone in interface Field

Overrides:

clone in class Object

Returns:

a clone of this field

getModifier

public String getModifier()

Returns the bandwith modifier.

Returns:

The bandwith modifier.

The allowed modifiers are defined by RFC 2327 and RFC 3556:

• AS: Application Specific
• CT: Conference Total
• RS: RCTP bandwith for data senders
• RR: RCTP bandwith for data receivers

getType

public char getType()

Returns the type character for the field.

Specified by:

getType in interface Field

Returns:

the field type character: b

getValue

public int getValue()

Returns the bandwith value.

Returns:

the bandwith value in kbits/second

setModifier

public void setModifier(String modifier)
                 throws SDPException

Sets the bandwith modifier.

Parameters:

modifier - the modifier to set

Throws:

SDPException - if the modifier is unknown

setValue

public void setValue(int value)
              throws SDPException

Sets the bandwith value.

Parameters:

value - the value to set

Throws:

SDPException - if value is negative

toString

public String toString()

Returns a string representation of the field. The representation has the form: b=<modifier>:<value>

Specified by:

toString in interface Field

Overrides:

toString in class Object

Returns:

the string representation of the field