Real-time transport protocol stream detection system and method
First Claim
1. A method for identifying UDP packets on an IP network which are candidates for characterization as a RTP packet of a Real Time Transport Protocol (RTP) stream, each of said UDP packets having a UDP header and a payload, wherein the payload potentially includes a RTP packet having a RTP header and a RTP payload, comprising the steps of:
- identifying UDP packets at a point on said IP network, and for each identified UDP packet performing the substeps of;
i. determining if a version number value in said RTP header located in the payload of said identified UDP packet equals a predetermined value, andii. determining if the packet length in said identified UDP packet header is within a predetermined range, andif said determining substeps are affirmative, then characterizing said identified UDP packet as a candidate RTP packet of an RTP stream,determining from said candidate RTP packet header;
a payload type, a SSRC, a sequence number, and a timestamp,comparing said determined SSRC, sequence number, and timestamp with a stored SSRC, a stored sequence number, and a stored timestamp of previously identified RTP streams, andcomparing said determined payload type with a stored payload type field of said previously identified RTP streams and at least one dynamic payload type associated with said previously identified RTP streams, andif there is a match in said comparison for one of said previously identified RTP streams, generating a signal associated with said candidate RTP packet denoting that said candidate RTP packet is a packet of said one previously identified RTP stream without regard to application level signaling associated with said one previously identified RTP stream.
3 Assignments
0 Petitions
Accused Products
Abstract
A system and method for identifying UDP packets on an IP network as candidates for characterization as packets of a RTP stream. UDP packets are identified at a point on the IP network, and for each identified UDP packet 1) it is determined if a version number in a RTP header field in the payload of the UDP packet equals a predetermined value, 2) determined if a packet length associated with the UDP packet is within a predetermined range, 3) determined if a payload type RTP header field within the payload of the UDP packet is within a predetermined range. If all the criteria are satisfied, then the identified UDP packet is characterized as a candidate RTP packet. It is then determined if the candidate RTP packet belongs to a previously detected RTP stream, or to a newly encountered RTP stream. A stream data store is then updated using the information in the RTP header of the candidate RTP packet.
53 Citations
22 Claims
-
1. A method for identifying UDP packets on an IP network which are candidates for characterization as a RTP packet of a Real Time Transport Protocol (RTP) stream, each of said UDP packets having a UDP header and a payload, wherein the payload potentially includes a RTP packet having a RTP header and a RTP payload, comprising the steps of:
-
identifying UDP packets at a point on said IP network, and for each identified UDP packet performing the substeps of; i. determining if a version number value in said RTP header located in the payload of said identified UDP packet equals a predetermined value, and ii. determining if the packet length in said identified UDP packet header is within a predetermined range, and if said determining substeps are affirmative, then characterizing said identified UDP packet as a candidate RTP packet of an RTP stream, determining from said candidate RTP packet header;
a payload type, a SSRC, a sequence number, and a timestamp,comparing said determined SSRC, sequence number, and timestamp with a stored SSRC, a stored sequence number, and a stored timestamp of previously identified RTP streams, and comparing said determined payload type with a stored payload type field of said previously identified RTP streams and at least one dynamic payload type associated with said previously identified RTP streams, and if there is a match in said comparison for one of said previously identified RTP streams, generating a signal associated with said candidate RTP packet denoting that said candidate RTP packet is a packet of said one previously identified RTP stream without regard to application level signaling associated with said one previously identified RTP stream. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
-
-
17. A system for identifying UDP packets on an IP network which are candidates for characterization as a packet of a Real Time Transport Protocol (RTP) stream, each of said UDP packets having a UDP header and a payload, wherein the payload potentially includes a RTP packet having a RTP header and a RTP payload, wherein each of said UDP packet headers includes a field for packet length corresponding to the size of said UDP packet, the system comprising:
-
an identification processor adapted to identify UDP packets at a point on said IP network, including characterization means operative on each identified UDP packet for; i. determining if a version number value in said RTP header located in the payload of said identified UDP packet equals a predetermined value, and ii. determining if the packet length in said identified UDP packet header is within a predetermined range, and if said determining substeps are affirmative, then characterizing said identified UDP packet as a candidate packet of an RTP stream, determine from said candidate RTP packet header;
a payload type, a SSRC, a sequence number and a timestamp,compare said determined SSRC, sequence number and timestamp with a stored SSRC, a stored sequence number, and a stored timestamp of a previously identified RTP stream, compare said determined payload type with a stored payload type field of said previously identified RTP stream and at least one dynamic payload type associated with said previously identified RTP stream, and if there is a match in said comparisons for one of said previously identified RTP streams, generate a signal associated with said candidate RTP packet denoting that said candidate RTP packet is a packet of said one previously identified RTP stream without regard to application level signaling associated with said one previously identified RTP stream. - View Dependent Claims (18, 19)
-
-
20. A non-transitory computer storage readable medium comprising computer executable instructions for identifying UDP packets on an IP network which are candidates for characterization as a packet of a Real Time Transport Protocol (RTP) stream, each of said UDP packets having a UDP header and a payload, wherein the payload potentially includes a RTP packet having a RTP header and a RTP payload, the computer storage readable medium comprising computer executable instructions for:
-
identifying UDP packets at a point on said IP network, and for each identified UDP packet performing the substeps of; i. determining if a version number value in said RTP header located in the payload of said identified UDP packet equals a predetermined value, and ii. determining if the packet length in said identified UDP packet header is within a predetermined range, and if said determining substeps are affirmative, then characterizing said identified UDP packet as a candidate packet of an RTP stream; determining from said candidate RTP packet header;
a payload type, a SSRC, a sequence number, and a timestamp,comparing said determined SSRC, sequence number, and timestamp with a stored SSRC, a stored sequence number, and a stored timestamp of previously identified RTP streams, and comparing said determined payload type with a stored payload type field of said previously identified RTP streams and at least one dynamic payload type associated with said previously identified RTP streams, and if there is a match in said comparison for one of said previously identified RTP streams, generating a signal associated with said candidate RTP packet denoting that said candidate RTP packet is a packet of said one previously identified RTP stream without regard to application level signaling associated with said one previously identified RTP stream. - View Dependent Claims (21, 22)
-
Specification