[sctp-dev] SCTP API - PPI
Christopher Hegarty - Sun Microsystems Ireland
Christopher.Hegarty at Sun.COM
Wed Dec 10 01:53:15 PST 2008
Great, you are actually using the PPID in some prototypes. I'll add a
getter/setter to MessageInfo for this. I hope to have an updated javadoc
early next week.
Kukosa, Tomas wrote:
> Hi Chris,
> I have understood RFC 4960 (see PPI definition below) in another way.
> It is not for future usage/flexibility. It is for usage of application
> layer to discern between various kinds of DATA chunks.
> Curently we use it just in our prototypes where we use PPI 13 (for
> H.323) and few proprietary PPIs.
> We use SCTP library from http://i1.dk/JavaSCTP/ but we are looking
> forvard to test SCTP in Java. :-)
> Best regards,
> RFC 4960 snip
> Payload Protocol Identifier: 32 bits (unsigned integer)
> This value represents an application (or upper layer) specified
> protocol identifier. This value is passed to SCTP by its upper
> layer and sent to its peer. This identifier is not used by SCTP
> but can be used by certain network entities, as well as by the
> peer application, to identify the type of information being
> carried in this DATA chunk. This field must be sent even in
> fragmented DATA chunks (to make sure it is available for agents in
> the middle of the network). Note that this field is NOT touched
> by an SCTP implementation; therefore, its byte order is NOT
> necessarily big endian. The upper layer is responsible for any
> byte order conversions to this field.
> The value 0 indicates that no application identifier is specified
> by the upper layer for this payload data.
>> -----Original Message-----
>> From: Christopher.Hegarty at Sun.COM
>> [mailto:Christopher.Hegarty at Sun.COM]
>> Sent: Tuesday, December 09, 2008 4:57 PM
>> To: Kukosa, Tomas
>> Cc: sctp-dev at openjdk.java.net
>> Subject: Re: [sctp-dev] SCTP API - PPI
>> Hi Tomas,
>> The Payload Protocol ID has been included in the protocol for future
>> flexibility. It is envisioned that the functions of protocol
>> identification and port number multiplexing will not be as closely
>> linked in the future as they are currently.
>> The current draft does not have support for getting/setting
>> the Payload
>> Protocol Identifier, PPID. You are correct, if we were to
>> support this
>> then it would be through a getter/setter in the MessageInfo class.
>> Do you have a specific requirement for the PPID?
>> On 12/09/08 14:42, Kukosa, Tomas wrote:
>>> looking to proposed API I can not see any method to set/get Payload
>>> Protocol Identifier.
>>> I would expect it e.g. in the MessageInfo class. Have I
>> missed anything?
>>> Best regards,
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