Packet data network voice call quality monitoring

• US 20030198218A1
• Filed: 05/21/2003
• Published: 10/23/2003
• Est. Priority Date: 03/11/1997
• Status: Active Grant

• Current Assignee: Verizon Patent and Licensing Incorporated (Verizon Communications Inc.)
• Original Assignee: Verizon Services Corporation (Verizon Communications Inc.)
• Inventors: Farris, Robert D., Voit, Eric A.
• Granted Patent: US 7,830,860 B2
• Time in Patent Office: Days
• US Class Current: 370/356
• CPC Class Codes: H04L 41/5009 Determining service level performance parameters or violations of service level contracts, e.g. violations of agreed response time or mean time between failures [MTBF]
• CPC Class Codes: H04L 41/5087 wherein the managed service relates to voice services management of VoIP services H04M7/0081
• CPC Class Codes: H04L 43/0829 Packet loss
• CPC Class Codes: H04L 43/0864 Round trip delays
• CPC Class Codes: H04L 43/087 Jitter
• CPC Class Codes: H04L 43/10 Active monitoring, e.g. heartbeat, ping or trace-route
• CPC Class Codes: H04L 43/16 Threshold monitoring
• CPC Class Codes: H04L 45/00 Routing or path finding of packets in data switching networks routing or path finding in wireless networks H04W40/00
• CPC Class Codes: H04L 45/22 Alternate routing
• CPC Class Codes: H04M 2207/12 intelligent networks
• CPC Class Codes: H04M 7/0057 Services where the data services network provides a telephone service in addition or as an alternative, e.g. for backup purposes, to the telephone service provided by the telephone services network
• CPC Class Codes: H04Q 3/0045 involving hybrid, i.e. a mixture of public and private, or multi-vendor systems

Abstract

The quality of service existing in a data packet network during the course of communication of a voice call through a data network, such as the Internet, is monitored. A minimum acceptable level of service may be predefined with a threshold quality level stored in the user'"'"'s Call Processing Record (CPR) in the AIN Integrated Services Control Point (ISCP). If the monitored quality is maintained in excess of the stored threshold, communication of the call continues through the established course of transmission. If the measured quality of service on the data network is not satisfactory, the routing of the call is changed to communication solely through a voice telephone network connection, which may include an Interexchange Carrier link, without terminating the call. The packet data network is thereby bypassed to obtain voice grade quality while maintaining the call.

Claims

1. A method of controlling voice communication between calling and called telephone stations each connected through a respective switch to a public switched telephone network (PSTN) region and remotely located from each-other, comprising the steps of:

routing a voice call between said calling and called stations in digital packet format through a path of a packet data network;

changing the route of said call from said packet data network path to a voice telephone network connection without terminating the call, thereby bypassing said packet data network while maintaining the call.

2. A method as recited in claim 1, wherein said changing step is responsive to a DTMF signal input by one of said stations.

3. A method as recited in claim 1, wherein said changing step comprises:

monitoring said packet data network during the course of transmission of said voice call through said path to determine a quality of performance level

comparing the performance level determined in said monitoring step with a predetermined threshold level; and

rerouting the call to the voice telephone network if the performance level of said packet data network as monitored in said monitoring step is below said predetermined threshold.

4. A method as recited in claim 3, wherein said data packet network is the Internet, which interfaces with a plurality of PSTN regions through respective Internet modules, and said rerouting step comprises:

transmitting a signal from an Internet module connected with the PSTN region of the calling station to the calling station switch;

in response to said signal, establishing a connection for said call from said calling station switch through the PSTN to a second switch coupled to the called station;

bridging the voice call at each of said switches to, the established connection; and

terminating communication of said call through said packet data network path.

5. A method as recited in claim 3, wherein said performance level is related to data flow rate and said predetermined threshold is a minimum acceptable voice transmission time, said monitoring step comprising:

transmitting at least one request packet through said data;

receiving at least one response packet; and

measuring the round trip time duration therebetween.

6. A method as recited in claim 4, wherein said predetermined threshold is a minimum acceptable data flow rate and said monitoring step comprises:

measuring the voice data packet pulses received per unit time period from the Internet at the Internet module connected to the PSTN region of the calling station.

7. A method as recited in claim 4, wherein said monitoring step comprises:

measuring the time variance between voice data packets received from the Internet at the Internet module connected to the PSTN region of the calling station; and

wherein said performance level is below said predetermined threshold if said measured time variance exceeds a maximum value.

8. A method as recited in claim 4, wherein said monitoring step comprises:

checking the sequence of voice data packets of the call received at the Internet module connected to the PSTN region of the calling station;

detecting whether voice data packets for the call have not been received in said checking step; and

said comparing step comprises determining whether the frequency of missed packets detected in said detecting step exceeds a maximum value.

9. A method as recited in claim 4, wherein said establishing step comprises:

transmitting a control signal from the PSTN region of said calling station to the PSTN region of said called station through a common channel signaling system path.

10. A method as recited in claim 3, wherein said data packet network interfaces with a plurality of PSTN regions through respective modules, and said rerouting step comprises:

transmitting a first signal from a module connected with the PSTN region of the calling station to the calling station switch;

transmitting a second signal from a module connected with the PSTN region of the called station to the called station switch;

in response to said first and second signals, establishing a connection for said call from said calling station switch through the PSTN to a second switch coupled to the called station;

bridging the voice call at each of said switches to the established connection; and

terminating communication of said call through said packet data network path.

11. A method as recited in claim 10, wherein said establishing step comprises:

transmitting an in-band control signal from the PSTN region of said calling station to the PSTN region of said called station through a voice communication trunk.

12. A communications network comprising:

a switched telecommunications network having interconnected central office switching systems and having subscriber lines connected to;

said central office switching systems providing connection between terminals connected to said subscriber lines, each of said central office switching systems responding to a service request on a subscriber line connected thereto to, selectively provide a communication connection between the requesting line and another selected subscriber line through the switched telecommunications network;

a separate control network for said switched telecommunications network comprising a common channel interoffice signaling network including signal transfer points connected to said central office switching systems through signal switching points via links between said signal switching points and signal transfer points;

a data network separate from said switched telephone network comprising multiple remotely spaced routers for linking together paths of said data network using transmission control protocols to provide connectionless packet service between remote locations of said data network;

at least two of said central office switching systems having connected thereto an interface to said data network, said central office switching systems providing selective connection between said interfaces and the subscriber lines connected to each of said central office switching systems;

each said interface comprising means for monitoring said data network during the course of communication of a voice call between a first and a second of said subscriber lines through said data network to determine a quality of performance level in said data network, and means for providing a signal to said control network indicating that said performance level is unacceptable;

whereby said control network is responsive to said signal to reroute said voice call through said switched telecommunications network to bypass said data network while maintaining the call.

13. A communication network as recited in claim 12, wherein said central office switching systems comprise means responsive to said control network for bridging said first and second subscriber lines the rerouted switched telecommunications path.

14. A communications system comprising:

a public switched telecommunications network (PSTN) having a plurality of interconnected central office switching systems each connected to at least one subscriber line;

a data network separate from said switched telephone network comprising multiple remotely spaced routers for linking together paths of said data network using transmission control protocols to provide connectionless packet service between remote locations of said data network;

at least two of said central office switching systems connected to a respective interface to said data network, said central office switching systems providing selective connection between said interfaces and the subscriber lines connected to each of said central office switching systems; and

means for automatically rerouting a voice call between subscriber lines of said two central office switching systems that traverse said data network to a voice path in said PSTN in response to a predetermined condition, without terminating the existing voice call.

15. A communications system as recited in claim 14, wherein said predetermined condition is receipt of a DTMF signal input from one of said subscriber lines.

16. A communications system as recited in claim 14, wherein said predetermined condition is the occurrence of an unacceptable level of quality of performance of said data network, and each said interface comprises means for monitoring said data network during the course of transmission of said voice call through said data network.

17. A communications system as recited in claim 16, wherein said monitoring means measures voice data packet pulses received per unit time period from the data network.

18. A communications system as recited in claim 16, wherein said monitoring means transmits a request packet through said data network, receives a response packet, and measures the round trip time duration therebetween.

19. A communications system as recited in claim 16, wherein said monitoring means measures time variance between voice data packets received from the data network.

20. A communications system as recited in claim 16, wherein said monitoring means detects lost voice data packets.