WO2009002304A1

WO2009002304A1 - Method and apparatus for remote stream reconstruction and monitoring

Info

Publication number: WO2009002304A1
Application number: PCT/US2007/014754
Authority: WO
Inventors: Jiwang Dai; Xiuping Lu; Alan Jay Stein
Original assignee: Thomson Licensing
Priority date: 2007-06-25
Filing date: 2007-06-25
Publication date: 2008-12-31

Abstract

There are provided methods and apparatus for remote stream reconstruction and monitoring. An apparatus for use in a network includes a packet re-constructor, disposed at a monitoring node. The packet re-constructor reconstructs an original packetized media stream as received by a monitored node using packet identification information and packet timing information relating to the original packetized media stream as received by the monitored node and further using the original packetized media stream as received from another node with respect to the monitoring node and the monitored node.

Description

METHOD AND APPARATUS FOR REMOTE STREAM RECONSTRUCTION

AND MONITORING

TECHNICAL FIELD

The present invention generally relates to media stream monitoring and, more particularly, to a method and apparatus for remote stream reconstruction and monitoring.

BACKGROUND

Remote monitoring of media stream quality is of high importance in the field of commercial media distribution. For example, in an Internet Protocol Television (IPTV) system, it is desirable to be able to monitor video quality at the deployed set top boxes (STBs) from a video service office. However, as the bandwidth of a media distribution network is often asymmetric, it is undesirable to route the actual video stream from the remote site back to the monitoring station. Prior art systems often execute video quality analyzing programs within the target device. In such systems, the target device sends only the analyzed data back to the monitoring station.

Such prior art systems are generally acceptable in most scenarios. However, such systems also have many limitations. Most quality analyzing programs only perform transportation layer packet analysis, which does not provide a precise measurement of the media stream quality per se. This is because each media packet could have a different level of importance to the overall quality of the media. For example, there may be three different types of compressed. pictures in a video stream compliant with the International Organization for

Standardization/International Electrotechnical Commission (ISO/IEC) Moving Picture Experts Group-2 (MPEG-2) standard, namely I₁ B and P pictures. A packet loss in an I picture might adversely impact all the pictures in its group of pictures (GOP), whereas a packet loss in a B picture only deteriorates or damages that particular picture itself.

Since packet level analysis has limitations in assessing the media quality, some prior art systems employ certain advanced and complex algorithms, some of which try to mimic the human subjective measurement to measure the media quality. However, even the most advanced algorithms cannot suitable substitute for actual human subjective measurement. More importantly, these algorithms hardly have the same pre-decoding or post decoding processes, such as error concealment and de-jitter buffering, as the ones in the actual end devices (e.g.,

STBs). Thus, the quality analysis generated from the algorithms may not exactly match the end users' experience.

Therefore, human subjective monitoring of the media quality is often desirable if not necessary. A visual inspection of the video is far more intuitive than reading the computer generated data report. Accordingly, in commercial digital TV broadcast systems, visual displaying and monitoring of all TV channels in the distribution office is commonly used.

When a human subjective measurement of media quality is desirable or necessary, prior art systems route a copy of the media stream from the remote site back to the monitoring station. One exemplary prior art system is implemented as a commercial video over Internet Protocol (IP) remote monitoring probe. This prior art system resides on the remote site where the video over IP quality needs to be measured. When a monitoring station requests a stream to display, the remote device routes the stream back to the monitoring station. Accordingly, such a prior art system has a number of disadvantages. For example, the preceding prior art system requires significant bandwidth to stream the data back to the monitoring station. Second, the stream sent to the monitoring station is not the exact or a close duplicate of the original stream as the stream was received by the remote device. For example, the jitter characteristics of the original stream are totally lost. Also, the replayed stream could suffer loss in the transmission back to the monitoring station. This further complicates the measurement.

FIG. 1 illustrates a remote monitoring system 100, in accordance with the prior art. A server (S) 180 transmits a stream So via a network 166 to a remote site (RS) 142, resulting in the remote site 142 (RS) receiving a version of the stream So₃.

The system 100 monitors stream So from the monitoring station (MS) 110. A remote agent (RA) 172 running at the remote site (RS) 142 sends the stream S'_Oa to monitoring station M 110 via network 166, resulting in monitoring station M 110 receiving a version of the stream S¹Oa- When the remote agent 172 streams SO_a. the remote agent 172 would typically preserve the exact packet order in So, but would not preserve the exact timing (e.g., jitters) in So. Therefore, the stream sent back from the remote site (RS) 142 is named as Soa to differentiate the same from S₀. After S o_a passes through the network 166 and arrives at monitoring station (MS) as stream S ₀, the stream timing information is further changed by the network 166, resulting in the stream S'Oa mentioned above.

FIG. 7 illustrates a Real-Time Control Protocol (RTCP) receiver report 700, in accordance with the prior art. As described in the RTP standard, RTP uses the standard receiver report 700 to report the receiving conditions and other parameters of the receiver side. However, the standard receiver report 700 only includes statistics of receiving conditions, such as inter-arrival jitter, cumulative number of packets lost and fraction lost. The standard receiver report 700 does not provide packet by packet information.

SUMMARY

These and other drawbacks and disadvantages of the prior art are addressed by the present principles, which are directed to methods and apparatus for remote stream reconstruction and monitoring.

According to an aspect of the present principles, there is provided an apparatus for monitoring a node in a network. The apparatus includes a communications interface coupled to a network and adapted to receive packetized data from a monitored node, and a processor coupled to the communications interface and adapted to reconstruct an original packetized media stream as received by the monitored node using packet identification information and packet timing information relating to the original packetized media stream transmitted by the monitored node and received by the communications interface, without receipt of the original packetized media stream from the monitored node. According to another aspect of the present principles, there is provided a method for monitoring a node in a network. The method includes the steps of receiving packet identification information and packet timing information relating to an original packetized media stream received at a monitored node, and reconstructing, without receipt of the receipt of the original packetized media stream from the monitored node, the original packetized media stream using packet identification information and packet timing information relating to the original packetized media stream as received by the monitored node.

According to another aspect of the present invention, there is provided an apparatus that provides information to a monitoring node in a network. The apparatus includes communications interface coupled to a network and adapted to receive a packetized media stream, and processor coupled to the communications interface and adapted to determine packet identification information and packet timing information relating to the received packetized media stream, which enables a monitoring node to reconstruct the packetized media stream as received by the apparatus, and causing the communications interface to transmit the packet identification information and packet timing information to the monitoring node. According to another aspect of the present invention, there is provided a method for providing information to a monitoring node in a network. The method includes receiving a packetized media stream, determining packet identification information and packet timing information relating to the received packetized media stream, which enables a monitoring node to reconstruct the packetized media stream as received, and transmitting the packet identification information and packet timing information to the monitoring node.

These and other aspects, features and advantages of the present principles will become apparent from the following detailed description of exemplary embodiments, which is to be read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The present principles may be better understood in accordance with the following exemplary figures, in which:

FIG. 1 illustrates a remote monitoring system, in accordance with the prior art; FIG. 2 shows a typical Internet Protocol Television (IPTV) system, to which the present principles may be applied, in accordance with an embodiment of the present principles; FIG. 3 illustrates a simplified version of a hierarchical network media delivery system, to which the present principles may be applied;

FIG. 4 illustrates a remote stream monitor for a hierarchical network, in accordance with an embodiment of the present principles; FIG. 5 shows a high-level block diagram of the stream re-constructor of FIG.

4, in accordance with an embodiment of the present principles;

FIG. 6 illustrates a Real-Time Control Protocol (RTCP) header to which the present principles may be applied, in accordance with an embodiment of the present principles; FIG. 7 illustrates a Real-Time Control Protocol (RTCP) receiver report packet format, in accordance with the prior art;

FIG. 8 illustrates a Real-Time Control Protocol (RTCP) receiver report packet format extended to convey timing information to a monitor, in accordance with an embodiment of the present principles; and FIG. 9 illustrates a method for remote stream reconstruction and monitoring in a hierarchical network, in accordance with an embodiment of the present principles.

DETAILED DESCRIPTION

The present principles are directed to a method and apparatus for remote stream reconstruction and monitoring.

The present description illustrates the present principles. It will thus be appreciated that those skilled in the art will be able to devise various arrangements that, although not explicitly described or shown herein, embody the present principles and are included within its spirit and scope. All examples and conditional language recited herein are intended for pedagogical purposes to aid the reader in understanding the present principles and the concepts contributed by the inventor(s) to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions. Moreover, all statements herein reciting principles, aspects, and embodiments of the present principles, as well as specific examples thereof, are intended to encompass both structural and functional equivalents thereof. Additionally, it is intended that such equivalents include bpth currently known equivalents as well as equivalents developed in the future, i.e., any elements developed that perform the same function, regardless of structure.

Thus, for example, it will be appreciated by those skilled in the art that the block diagrams presented herein represent conceptual views of illustrative circuitry embodying the present principles. Similarly, it will be appreciated that any flow charts, flow diagrams, state transition diagrams, pseudocode, and the like represent various processes which may be substantially represented in computer readable media and so executed by a computer or processor, whether or not such computer or processor is explicitly shown.

The functions of the various elements shown in the figures may be provided through the use of dedicated hardware as well as hardware capable of executing software in association with appropriate software. When provided by a processor, the functions may be provided by a single dedicated processor, by a single shared processor, or by a plurality of individual processors, some of which may be shared. Moreover, explicit use of the term "processor" or "controller" should not be construed to refer exclusively to hardware capable of executing software, and may implicitly include, without limitation, digital signal processor ("DSP") hardware, read-only memory ("ROM") for storing software, random access memory ("RAM"), and non-volatile storage.

Other hardware, conventional and/or custom, may also be included. Similarly, any switches shown in the figures are conceptual only. Their function may be carried out through the operation of program logic, through dedicated logic, through the interaction of program control and dedicated logic, or even manually, the particular technique being selectable by the implementer as more specifically understood from the context.

In the claims hereof, any element expressed as a means for performing a specified function is intended to encompass any way of performing that function including, for example, a) a combination of circuit elements that performs that function or b) software in any form, including, therefore, firmware, microcode or the like, combined with appropriate circuitry for executing that software to perform the function. The present principles as defined by such claims reside in the fact that the functionalities provided by the various recited means are combined and brought together in the manner which the claims call for. It is thus regarded that any means that can provide those functionalities are equivalent to those shown herein.

Reference in the specification to "one embodiment" or "an embodiment" of the present principles means that a particular feature, structure, characteristic, and so forth described in connection with the embodiment is included in at least one embodiment of the present principles. Thus, the appearances of the phrase "in one embodiment" or "in an embodiment" appearing in various places throughout the specification are not necessarily all referring to the same embodiment. It is to be appreciated that while at least some of the embodiments of the present principles described herein involve a hierarchical network, the present principles are not limited to the same, and may be used with respect to other types of networks while maintaining the spirit of the present principles. Accordingly, any relationships between nodes as described with respect to a hierarchical network may not be necessary in other embodiments of the present principles that involve networks other than hierarchical networks and, further, may not be necessary in other embodiments of the present principles that nonetheless involve hierarchical networks. These and other variations and implementations of the present principles are readily contemplated by one of ordinary skill in this and related arts, given the teachings of the present principles provided herein, while maintaining the spirit of the present principles.

The present principles are directed to a method and apparatus for remote stream reconstruction and monitoring. The present principles may used, for example, with respect to a particular node in a hieratical network to reconstruct and monitor a packetized media stream distributed at the downstream nodes with respect to the particular node. The present principles take advantage of the fact that all packets of the media stream distributed to the downstream nodes are available at their parent or grandparent nodes. Thus, in accordance with the present principles, an upstream node in a hieratical network only has to acquire packet identification and packet timing information from a monitored downstream node in order to reconstruct the exact stream in the downstream node.

Advantageously, the present principles allow the upstream node to reconstruct and monitor the media stream of its downstream nodes with only a small fraction of the stream bit rate. It is to be appreciated that the present principles may be utilized in many disparate applications involving stream reconstruction and monitoring. For example, one exemplary application is to remotely and visually monitor the video quality of a central office from its parent video hub office in a

TELCO IPTV system. Given the teachings of the present principles provided herein, these and other applications of the present principles are readily ascertained by one of ordinary skill in this and related arts, while maintaining the spirit of the present principles. Commercial media stream distribution systems are often hieratical. FIG. 2 shows a typical Telco Internet Protocol Television (IPTV) system 200, to which the present principles may be applied, in accordance with an embodiment of the present principles. TV programs are multicast from redundant super head-ends (SHE) 210 to multiple metro video hub offices (VHO) 220. Each VHO 220 then further distributes the streams to multiple video enabled central offices (COs) (which are also referred to as video service offices (VSOs)) 230, from which streams are multicast to households 240.

The super head-ends 210 and the metro video hub offices 220 may be connected over an IP/MPLS core network 282. The video service offices 230 may be connected over a metro aggregation network 284. Each video service office 230 may be connected to each household 240 over an access network 286 using a Digital Subscriber Line Access Multiplexer (DLSAM) 288 which, in turn, may be connected to one or more remote terminals (also referred to herein as "set top boxes (STBs)) 273. The remote terminals 273 may correspond to, for example, a household, a business, an institution (e.g., school, etc.), and so forth. A household 240 may include, for example, a television 242, a phone 244, and a computer 246. In such systems, stream quality monitoring stations are often located at the upper stream nodes to monitor the streams at the downstream nodes. For example, in an IPTV system, it is often the requirement for the video hub office 220 to be able to monitor the remote video or audio quality in its downstream video service offices 230, or set-top boxes 273, and not the other way around. Similarly, a super headend 210 would typically monitor the video/audio qualities in downstream video service offices 230, so the super head-end 210 can assess the quality of the media delivery in the backbone network (e.g., network 282).

In such hieratical systems, all packets in the media stream to be monitored are actually available to the monitoring station. However, the actual packet timing, ordering and integrity at the remote device are not available to the monitoring station.

FIG. 3 illustrates a simplified version of a hierarchical network media delivery system 300, to which the present principles may be applied. A server (S) 380 transmits a multimedia stream So via a network 366 to multiple remote sites, namely remote site (RS) 342, remote site (RS) RB 344, and remote site (RS) 346.

A monitoring station (MS) 310 is located close to the server (S) 320. The server (S) 180 may be, for example, but is not limited to, a multicast server. Stream So is accessible to monitoring station (MS) 310.

The network 366 can introduced various impairments, such as jitter, latency, loss and packet reordering, to stream S₀. Therefore, stream Soa. So_b and S<j_c that arrive at remote site (RS) 342, remote site (RS) RB 344, and remote site (RS) 346, could have deteriorated media quality. However, all packets in So_a> Sob and So_c are included in So.

In contrast to the prior art approaches, the present principles take advantage of the fact that if the remote device transmits the packet timing information and packet ordering information, the monitoring station can use this information along with the media stream to reconstruct the stream at the remote site. Moreover, in some embodiments, the packet integrity information (e.g., lost packets, etc.) may also be transmitting from the remote device to the monitoring station for use in reconstructing the stream.

FIG. 4 illustrates a remote stream monitor 400 for a hierarchical network, in accordance with an embodiment of the present principles.

In FIG. 4, the monitoring station (MS) 410 includes a monitor 412 and a stream re-constructor (SRC) 414. The monitor 412 allows a user to visually view and, hence, monitor, the stream S^*oa created per the present principles. A server (S) 480 transmits a multimedia stream So via a network 466 to remote site (RS) 442.

In contrast to the prior art approaches which send the actual stream So_a back to the monitoring station, the remote site (RS) 442 sends packet identification (e.g., the packet identifier or PID) and timing information T_Oa (e.g., presentation time stamp (PTS), decode time stamp (DTS), sequence number (SN), and so forth) through a reliable transport protocol (for example, but not limited to, transport control protocol (TCP)) to the monitoring station (MS) 410. The stream re-constructor (SRC) 414 receives T₀₃ and the original (reference) stream So and creates stream S^*oa. which theoretically can carry the same packets with the same timing characteristics of S_Oa of the remote site. The stream re-constructor may comprise a receiver and a processor programmed to reconstruct the stream using the received packet timing information.

While one remote site is shown in FIG. 4, it is to be appreciated that the present principles may be employed in networks having a plurality of remote sites with respect to the server. Moreover, while one server (S) 480 is shown in FIG. 4, it is to be appreciated that the present principles may be employed in network having a plurality of servers. Further, while the monitor 412 and the stream re-constructor (RCS) 414 are shown as separate elements, in other embodiments the. monitor 412 and the stream re-constructor (RCS) 414 may be combined. Accordingly, the monitor 412 and stream re-constructor (SRC) 414 are also collectively referred to herein as a "monitor" and a "monitoring station". The preceding modifications to the elements of FIG. 4 are merely illustrative and, given the teachings of the present principles provided herein, it is to be appreciated that other modifications to the elements of FIG. 4 may be readily contemplated and implemented by one of ordinary skill in this and related arts, while maintaining the spirit of the present principles. FIG. 5 shows a block diagram of the stream re-constructor 414 of FIG. 4, in accordance with an embodiment of the present principles. The stream re- constructor 414 includes a packet buffer 510 and a packet processor 520.

Packets from the reference stream So are received and buffered in the packet buffer 510. The timing information stream (T_Oa) sent from the remote site (RS) 442 is received by the packet processor 520. The packet processor 520 uses the packet ID in the timing information stream To_a to read corresponding packets from the packet buffer 510 and sends them to the monitor 412 as a new stream S^* _Oa> which has the same packet order and substantially close timing characteristics as the stream Soa in the remote site (RS) 442.

FIG. 6 illustrates a Real-Time Control Protocol (RTCP) header 600 to which the present principles may be applied, in accordance with an embodiment of the present principles. FlG. 8 illustrates a Real-Time Control Protocol (RTCP) receiver report packet format 800, in accordance with an embodiment of the present principles. The RTCP header 600 and the RTCP receiver report packet format 800 correspond to implementation involving Real-Time Protocol (RTP) stream.

In RTP₁ each packet is uniquely identified by the sequence number, as shown in FIG. 6. As described in the RTP standard, RTP uses the standard receiver report packet format 700 shown in FIG. 7 to report the receiving conditions and other parameters of the receiver side. However, the standard receiver report packet format 700 only includes statistics of receiving conditions, such as inter-arrival jitter, cumulative number of packets lost and fraction lost. The standard receiver report packet format 700 does not provide packet by packet information. The receiver report 800 will be transported reliably back to remote site (RS) 412.

The receiver report packet format 800 shown in FIG. 8 in accordance with an embodiment of the present principles can be used to achieve this goal. The receiver report packet format 800 includes a 64-bit Network Time Protocol (NTP) timestamp 810 and the sequence number 820 of each received packet. Thus, the receiver report packet format 800 includes enough information for the monitoring station 410 to recreate the stream at the remote site (RS) 412.

FIG. 9 illustrates a method 900 for remote stream reconstruction and monitoring in a hierarchical network, in accordance with an embodiment of the present principles. For illustrative purposes, the remote stream reconstruction and monitoring performed by method 900 is referred to as being performed at a "monitoring node".

The method 900 includes a start block 905 that passes control to a function block 910. The function block 910 receives the original (reference) stream So, at the monitoring node from a hierarchically higher node, and passes control to a function block 915. This original (reference) stream S₀ is also sent to at least one hierarchically lower node (hereinafter also referred to as a "monitored node", which would correspond to the remote sites (RS) shown in the other figures, such as elements 442 in FIG. 4). The original (reference) stream So received at the monitoring node may be stored thereat, for example, in the packet buffer 510.

The function block 915 receives packet identification information and timing information T_Oa through a reliable transport protocol at the monitoring node from a hierarchically higher node, and passes control to a function block 920.

The function block 920 reconstructs the original (reference) stream So as a newly created (reconstructed) stream S^* _Oa, using the received original (reference) stream So and the packet identification information and the timing information T_Oa (and optionally, packet integrity information), and passes control to a function block 925. Such reconstruction may be performed, for example, by the stream re- constructor 520, extracting packets from the packet buffer 510 as described herein.

The function block 925 visually displays the reconstructed stream S^*o_a to allow a user to visually view and, hence, monitor, the reconstructed stream S^*oa created per the present principles, and passes control to an end block 999. The reconstructed stream S^*oa may be viewed on monitor 412.

The principles of the present invention is also applied to a remote device that receives the media data stream and transmits packet identification and packet timing information to the monitoring station. As discussed above, prior art system transmit the received media data stream to the monitoring station. However, a remote device according to the present invention, e.g., a set top box, determines and transmit the above discussed packet identification information and packet timing information to the monitoring station. Such a remote device comprises, for example, a communications interface that may be coupled to a network for receiving a media data stream. The remote device includes a processor that determines based on the data received at the communications interface the packet identification information and the packet timing associated with each of the media stream packets. The processor then stores the information in a buffer or other suitable memory devices. When requested by the monitoring station, the remote device reads the necessary information from the buffer, or memory locations, and formats the necessary packets described above, and transmits the information, via the communications interface, to the monitoring station. The principles of the present invention are also applied to a method for transmitting monitoring information in a remote device. According to the present invention, as each packet of the media data stream is received, a processor of the remote device, e.g., a set top box, determines the packet identification information and packet timing information associated with the packet, and stores the information in a memory device. When requested by the monitoring device, the remote device reads the packet information from the memory device and formats a message as described hereinabove for transmission to the monitoring station. The remote device then transmits the messages using a communications interface via the network to the monitoring station. Alternatively, the packet identifying information and packet timing information may be sent in real time as the data is received by the remote device, without first storing the information in a storage device.

These and other features and advantages of the present principles may be readily ascertained by one of ordinary skill in the pertinent art based on the teachings herein. It is to be understood that the teachings of the present principles may be implemented in various forms of hardware, software, firmware, special purpose processors, or combinations thereof.

Preferably, the teachings of the present principles are implemented as a combination of hardware and software. Moreover, the software may be implemented as an application program tangibly embodied on a program storage unit. The application program may be uploaded to, and executed by, a machine comprising any suitable architecture. Preferably, the machine is implemented on a computer platform having hardware such as one or more central processing units ("CPU"), a random access memory ("RAM"), and input/output ("I/O") interfaces. The computer platform may also include an operating system and microinstruction code. The various processes and functions described herein may be either part of the microinstruction code or part of the application program, or any combination thereof, which may be executed by a CPU. In addition, various other peripheral units may be connected to the computer platform such as an additional data storage unit and a printing unit.

It is to be further understood that, because some of the constituent system components and methods depicted in the accompanying drawings are preferably implemented in software, the actual connections between the system components or the process function blocks may differ depending upon the manner in which the present principles are programmed. Given the teachings herein, one of ordinary skill in the pertinent art will be able to contemplate these and similar implementations or configurations of the present principles.

Although the illustrative embodiments have been described herein with reference to the accompanying drawings, it is to be understood that the present principles is not limited to those precise embodiments, and that various changes and modifications may be effected therein by one of ordinary skill in the pertinent art without departing from the scope or spirit of the present principles. All such changes and modifications are intended to be included within the scope of the present principles as set forth in the appended claims.

Claims

CLAIMS:

1. An apparatus, comprising:

S communications interface coupled to a network and adapted to receive packetized data from a monitored node; processor coupled to the communications interface and adapted to reconstruct an original packetized media stream as received by the monitored node using packet identification information and packet timing information relating to the0 original packetized media stream transmitted by the monitored node and received by the communications interface, without receipt of the original packetized media stream from the monitored node.

2. The apparatus of claim 1 , wherein the original packetized media5 stream is reconstructed further using packet integrity information relating to the original packetized media stream as transmitted by the monitored node.

3. The apparatus of claim 1 , wherein the processor monitors packetized media stream transmitted in an Internet Protocol Television system. 0

4. The apparatus of claim 1 , wherein the packet identification information and the packet timing information are received using transport control protocol (TCP).

5 5. The apparatus of claim 1 , wherein the apparatus further comprises: a packet buffer (510) that stores the original packetized media stream therein, the processor reconstructing the original packetized media stream as received by the monitored node by extracting corresponding packets from the original packetized media stream stored in the packet buffer using the packet identification information0 and packet timing information.

6. The apparatus of claim 1 , wherein at least one of the packet identification information and the packet timing information are received in a realtime control transport protocol (RTCP) receiver report.

7. The apparatus of claim 1 , wherein the network is a hierarchical network and the apparatus is hierarchically higher than the monitored node.

8. A method, comprising: receiving packet identification information and packet timing information relating to an original packetized media stream received at a monitored node; and reconstructing, without receipt of the receipt of the original packetized media stream from the monitored node, the original packetized media stream using packet identification information and packet timing information relating to the original packetized media stream as received by the monitored node.

9. The method of claim 8, wherein the original packetized media stream is reconstructed further using packet integrity information relating to the original packetized media stream as received by the monitored node.

10. The method of claim 8, wherein the original packetized media stream is transmitted in accordance with an Internet Protocol Television system.

11. The method of claim 8, wherein the receiving step comprises receiving the packet identification information and the packet timing information via transport control protocol (TCP).

12. The method of claim 8, wherein said re-constructing step comprises: receiving (910) the original packetized media stream from another node; storing the original packetized media stream received from the another node; and reconstructing (920) the original packetized media stream as received by the monitored node by extracting corresponding packets from the stored original packetized media stream using the packet identification information and packet timing information.

13. The method of claim 8, wherein at least one of the packet identification information and the packet timing information are received in a real-time control transport protocol (RTCP) receiver report.

14. An apparatus, comprising: communications interface coupled to a network and adapted to receive a packetized media stream; and processor coupled to the communications interface and adapted to determine packet identification information and packet timing information relating to the received packetized media stream, which enables a monitoring node to reconstruct the packetized media stream as received by the apparatus, and causing the communications interface to transmit the packet identification information and packet timing information to the monitoring node.

15. The apparatus of claim 14, wherein the apparatus further determines and causes the transmission of packet integrity information relating to the original packetized media stream to the monitoring node.

16. The apparatus of claim 14, wherein the packetized media stream is transmitted in an Internet Protocol Television system.

17. The apparatus of claim 14, wherein the packet identification information and the packet timing information are transmitted using transport control protocol (TCP).

18. The apparatus of claim 14, wherein at least one of the packet identification information and the packet timing information are transmitted in a realtime control transport protocol (RTCP) receiver report.

19. A method, comprising: receiving a packetized media stream; determining packet identification information and packet timing information relating to the received packetized media stream, which enables a monitoring node to reconstruct the packetized media stream as received; and transmitting the packet identification information and packet timing information to the monitoring node.

20. The method of claim 19, further comprising the step of determining packet integrity information relating to the original packetized media stream, and transmitting the packet integrity information to the monitoring node.

21. The method of claim 19, wherein the packetized media stream is transmitted in an Internet Protocol Television system. .

22. The method of claim 19, wherein the transmitting step comprises transmitting packet identification information and the packet timing information using transport control protocol (TCP).

23. The method of claim 19, wherein the transmitting step comprises transmitting at least one of the packet identification information and the packet timing information in a real-time control transport protocol (RTCP) receiver report.