BROWN BRUCE (US)
| US20020145979A1 | 2002-10-10 | |||
| US20020167937A1 | 2002-11-14 |
| 1. | A method of testing the performance of a VoIP communications network comprising providing a test pattern, transmitting the test pattern over at least part of the network to a test node and examining the test pattern received at the test node to determine the performance of the network. |
| 2. | A method as claimed in claim 1 wherein the test pattern received at the test node is compared with the originally transmitted test pattern. |
| 3. | A method as claimed in claim 1 wherein the test node requests a test connection and a test connection is established between network nodes to transmit the test pattern to the test node. |
| 4. | A method as claimed in claim 3 wherein the test pattern is transmitted from and received by the test node over the test connection. |
| 5. | A method as claimed in claim 3 wherein the test pattern originates from a node other than the test node. |
| 6. | A method as claimed in claim 3 wherein the test connection includes a media gateway. |
| 7. | A method as claimed in claim 6 wherein the test connection includes a further media gateway. |
| 8. | A method as claimed in claim 3 wherein the test connection request is interpreted into a number supported by a network node. |
| 9. | A method as claimed in claim 8 wherein the number is supported by a media gateway. |
| 10. | A method as claimed in claim 1 wherein the test node is a remote office test line device. |
| 11. | A method of testing the performance of at least a part of a VoIP communications network comprising the steps of : requesting by a remote office test line device a test connection ; receiving by a network switch the test request; the network switch acting upon the test request to inform network nodes to form the test connection; transmitting over the test connection a test pattern; receiving at the remote office test line device the transmitted test pattern; examining the received transmitted test pattern to determine therefrom the performance of the at least a part of the VoIP communications network. |
| 12. | Apparatus to test performance of a communications path in a VoIP communications network comprising: a test node for requesting a test ; a connection manager responsive to the test request to establish a connection path including the test node and other network nodes ; a test pattern transmitter to transmit a test pattern over the connection path; and a test pattern analyser to analyse the transmitted test pattern received over the connection path to determine therefrom the performance of the connection path. |
| 13. | Apparatus as claimed in claim 12 wherein the test node is a remote office test line device. |
| 14. | Apparatus as claimed in claim 12 wherein the connection manager is a switch. |
| 15. | Apparatus as claimed in claim 14 wherein the switch is a softswitch. |
| 16. | Apparatus as claimed in claim 12 wherein the connection path includes a media gateway. |
| 17. | Apparatus as claimed in claim 16 wherein the connection path includes a further media gateway. |
| 18. | Apparatus as claimed in claim 12 wherein the connection manager interprets the test request into a destination number supported by another network node. |
| 19. | Apparatus as claimed in claim 12 wherein the node transmitting the test pattern also receives the transmitted pattern over the test connection. |
| 20. | Apparatus as claimed in claim 12 wherein the test node includes an analyser to analyse a received transmitted test pattern to determine the performance of the test connection. |
| 21. | Apparatus as claimed in claim 20 wherein the analyser compares the received transmitted test pattern with the original test pattern. |
Field of the invention This invention relates to a VolP communications network testing method and apparatus.
Description of background to the invention Voice over IP communications networks are networks which utilise the Internet Protocol to transmit voice over data networks. The data network may be the Internet or a company's intrant or managed networks provided by internet service providers. Such networks are r,. popular since they provide one network which can handle both data and voice communications, there are potential cost savings and such networks enable the convenient provision of additional services.
It is desirable to provide a method or a network which can test the performance of the network or parts of the network.
Brief summary of the invention According to the invention there is provided a method of testing a VoIP communications network comprising providing a test pattern, transmitting the test pattern over at least part of the network to a node and examining the test pattern received at the node.
The test pattern may be transmitted from a first network node to a second network node and then the test pattern is examined or alternatively the pattern may be transmitted to a series of nodes ending in the originating node and then the step of examining the transmitted test pattern is carried out.
The step of examining the transmitted test pattern may comprise a comparison of the transmitted pattern with a pre-stored test pattern.
The test pattern may be considered as a test signal and in one embodiment of the invention is a. wav based signal.
In one embodiment of the invention a test pattern is sent from a Time Division Multiplexing (TDM) side of a media gateway to another media gateway which loops the test pattern back.
In a second embodiment of the invention a test pattern is sent from within the IP network to a media gateway from whence it is looped back to the IP network.
In a further embodiment, a test pattern is sent from a media gateway to a remote office test line device on the TDM network where it is then examined.
In a yet further embodiment, a test pattern is sent from a media gateway to a remote office test line device in an IP network where it is then examined. In this way one path of the network may be tested rather than a loop involving two paths outward and return.
The invention also provides apparatus.
Brief description of the drawings Figures 1 and 3 show VoIP communications networks operating in accordance with embodiments of the invention ; and Figures 2 and 4 show data flow diagrams for the communications networks shown in figures 1 and 3.
Detailed description of the drawings As is shown in figure 1, a VoIP communications network includes a softswitch 2, network nodes 3,4, media gateways 5,6 a remote office test line device 7 and an SS7 network 8. The softswitch 2 is one from the hiQ 8000/9200 TM family sold by Siemens Information and Communication Networks. A full specification for this equipment is available from the manufacturer under the following reference SURPASS hiQ 8000 Feature Description Guide, Part number A30828-X1121-A215-02-7671. The media gateways 5 and 6 are from the hiG 1200 family of products also available from Siemens Information and Communications Networks and specified in SURPASS hiG 1200 NMC-SE Administration Guide For Solaris, Part number A30828-X1121-A186-03-7671. The ROTL device is in this embodiment a PowerProbe 6000 by Minacom. The PowerProbe 6000 is capable of examining speech patterns by providing
Perceptual Evaluation of Speech Quality measurements based on ITU's P862 recommendations (Perceptual evaluation of speech quality (PESQ): An objective method for end-to-end speech quality assessment of narrow-band telephone networks and speech codecs, P. 862, TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU, 02/2001). This embodiment of the invention tests the communications path quality by transmission of a test pattern from the ROTL device 7 to the media gateway 6 and back to the ROTL device where it is compared with the pattern that was sent. The test pattern is a fragment of speech held as a. wav file.
In a first step, the ROTL device 7 signals via the SS7 network via the A or F link to the softswitch 2 that it wishes to perform a test to a. particular test NPA-NXX number. The softswitch 2 interprets the test destination NPA-NXX into a unique test Media Gateway Control Protocol End Point in the media gateway 6.
A Create Connection command"netwloop"is sent from the softswitch 2 to the media gateway 6 to create a connection between the ROTL device 7 and the media gateway 6. The connection is a loop back connection resulting in a looped test path including the ROTL device 7, the nodes 3 and 4 and the media gateway 6. The softswitch 2 then sends a command to create a connection on the ROTL device 7 with the mode set to send/receive. With the connection completed, the ROTL device 7 transmits a test pattern to the media gateway 6 from whence it is returned. The ROTL device then performs a comparison between the sent and the received patterns to determine the signal quality.
Figure 2 shows the call flow involved in this embodiment of the invention.
Figure 3 shows a further embodiment of the invention in which like components bear the same reference numerals as the first embodiment. In this embodiment, the ROTL device 7 is a Time Division Multiplexing (TDM) based device. In a first step, the ROTL device sends a signal via the SS7 network to the softswitch 2 that it wishes to perform a test to a particular test NPA-NXX number. The softswitch 2 interprets in a next step an originating point code and circuit identification code sent by the ROTL device 7 into a unique test MGCP end point. It further interprets the test destination NPA-NXX into a unique test MGCP end point in the destination media gateway 6.
In the next step, the softswitch 2 sends a MGCP CRCX command to the gateway 6 with the mode 4'netwloop". Then the softswitch 2 sends a MGCP command to the media gateway 5 to which the ROTL device 7 is connected to create a connection.
With the connection completed, the ROTL device 7 sends the test pattern over the looped test path between the device itself and the media gateways 5 and 6. The test signal is looped back from the media gateway 6 to the media gateway 5 and thence to the ROTL device 7.
The ROTL device 7 then compares the returned signal with that originally transmitted and analyzed to determine the quality. With
the test completed, the softswitch 2 is signalled and the call is released. The call flow is illustrated in figure 4.
In the aforementioned embodiments a pattern or test signal is sent from the ROTL device to another network element and returned to the device. The returned signal is then analysed. Thus the test signal will have travelled on an outward and return path. It may be desirable in some circumstances to test just one path.
In the third embodiment of the invention which will be explained utilising the communications network depicted in figure 1, the ROTL device 7 initiates a test and a network node transmits a test pattern to the ROTL device 7. The ROTL device 7 holds a copy of the original pattern against which the received pattern is compared to form an analysis of the quality of the communications path. A. wav file is provided to the ROTL device 7 and also the media gateway 6.
In a first step, the ROTL device 7 signals to the softswitch 2 via the SS7 network that it wishes to perform a test to a test number NPA- NXX. The softswitch 2 interprets the originating point code and the circuit identification code sent by the ROTL device 7 into an MGCP end point. It also interprets the test destination into unique test MGCP end point in the destination media gateway 6. The softswitch then transmits to that gateway an MGCP command"send". The softswitch 2 also send a command to the ROTL device 7 to "receive". With the connection completed, the test pattern is sent from the media gateway to the ROTL device 2 where it is received and analysed against a stored signal.
When the test is completed the ROTL device 7 signals the softswitch 2 to release the connection.
By a combination of the methods the location in the network of a poorly performing path may be identified.