Intelligent call tracking to detect drops using S1-AP and SIP signaling

• US 10,111,147 B1
• Filed: 10/06/2017
• Issued: 10/23/2018
• Est. Priority Date: 10/06/2017
• Status: Active Grant

• Current Assignee: NetScout Systems Incorporated
• Original Assignee: NetScout Systems Incorporated
• Inventors: Prasad, Sandeep, Saraswati, Abhishek, Liubinskas, Tauras, Uysal, Erdem, Guerrini, Claudio, Nadkarni, Rajeev, Bass, Brandon Wayne
• Primary Examiner(s): Ajayi, Joel
• Application Number:
  US15/727,409
• Time in Patent Office: 382 Days
• Field of Search: 455436
• CPC Class Codes: H04L 41/0631 using root cause analysis; using analysis of correlation between notifications, alarms or events based on decision criteria, e.g. hierarchy, tree or time analysis
• CPC Class Codes: H04L 41/0893 Assignment of logical groups to network elements
• CPC Class Codes: H04L 43/0823 Errors, e.g. transmission errors
• CPC Class Codes: H04L 43/16 Threshold monitoring
• CPC Class Codes: H04L 65/1104 Session initiation protocol [SIP]
• CPC Class Codes: H04L 65/80 Responding to QoS
• CPC Class Codes: H04M 2203/2088 Call or conference reconnect, e.g. resulting from isdn terminal portability
• CPC Class Codes: H04M 3/2218 Call detail recording
• CPC Class Codes: H04M 3/42 Systems providing special services or facilities to subscribers specially adapted for wireless communication networks H04W4/00
• CPC Class Codes: H04W 36/0022 for transferring data sessions between adjacent core network technologies
• CPC Class Codes: H04W 36/008375 based on historical data
• CPC Class Codes: H04W 36/16 Performing reselection for specific purposes

Abstract

A plurality of data packets is received from a wireless communication system. At least one of SIP signaling messages and S1-AP signaling messages associated with calls being made or attempted in the wireless communication system are analyzed for a specified time period to identify one or more dropped calls. At least one of SIP signaling error codes and S1-AP signaling cause codes associated with the identified dropped calls are analyzed to identify one or more call drop reasons. An ASI data set is generated based on the analysis of the at least one of the SIP signaling messages and the S1-AP signaling messages and based on the analysis of the at least one of the SIP signaling error codes and the S1-AP signaling cause codes.

Claims

1. A method for tracking a status of a call in a wireless communication system including an eNodeB and a Mobile Management Entity (MME), the method comprising steps of:

receiving, by a processor, a plurality of data packets from the wireless communication system;

analyzing, by a processor, S1-Application Protocol (S1-AP) signaling messages exchanged between the eNodeB and the MME over a first interface for the specified time period and analyzing bearer related events and one or more error codes associated with the bearer related events, the S1-AP signaling messages associated with live calls being made or attempted in the wireless communication system to identify one or more dropped calls;

tracking S1-AP session information corresponding to the analyzed S1-AP messages, wherein each tracked S1-AP session maintains one or more E-Radio Access Bearer (E-RAB) QoS class identifiers (QCI) values for each E-RAB associated with the S1-AP session;

analyzing, by a processor, S1-AP signaling cause codes associated with the one or more identified dropped calls to identify one or more call drop reasons; and

generating, by a processor, an Adaptive Session Intelligence (ASI) data set based on the combined analysis of the S1-AP signaling messages, one or more QCI values and of the S1-AP signaling cause codes, wherein the ASI data set includes one or more metrics indicative of E-RAB status at different stages of a corresponding live call.

2. The method of claim 1, wherein the step of analyzing the S1-AP signaling messages comprises partitioning the E-RAB QCI values into a plurality of groups.

3. The method of claim 2, wherein the step of analyzing the S1-AP signaling messages comprises analyzing at least one of the following messages:

INITIAL CONTEXT SETUP RESPONSE, INITIAL CONTEXT SETUP FAILURE, E-RAB SETUP RESPONSE, UE CONTEXT MODIFICATION FAILURE, E-RAB MODIFY RESPONSE, HANDOVER REQUEST ACKNOWLEDGE, HANDOVER PREPARATION FAILURE, HANDOVER COMMAND, HANDOVER FAILURE, PATH SWITCH REQUEST ACKNOWLEDGE, PATH SWITCH REQUEST FAILURE, E-RAB RELEASE COMMAND, E-RAB RELEASE RESPONSE, E-RAB RELEASE INDICATION and UE CONTEXT RELEASE REQUEST.

4. The method of claim 2, wherein the step of analyzing the S1-AP signaling messages comprises tracking a plurality of S1-AP attributes comprising International Mobile Subscriber Identity (IMSI), cell Id, International Mobile Equipment Identity (IMEI), Tracking Area Identity (TAI) and E-NodeB identity.

5. The method of claim 3, wherein the step of analyzing the messages further comprises tracking success and failure metrics for each of the plurality of groups.

6. The method of claim 5, wherein the plurality of groups comprises at least a voice bearer group.

7. A network device for tracking a status of a call in a wireless communication system, the network device comprising:

a network interface configured to receive program instructions to receive a plurality of data packets from the wireless communication system; and

a call tracking engine configured to;

analyze S1-Application Protocol (S1-AP) signaling messages exchanged between the eNodeB and the MME over a first interface for the specified time period and analyzing bearer related events and one or more error codes associated with the bearer related events, the S1-AP signaling messages associated with live calls being made or attempted in the wireless communication system to identify one or more dropped calls;

track S1-AP session information corresponding to the analyzed S1-AP messages, wherein each tracked S1-AP session maintains one or more E-Radio Access Bearer (E-RAB) QoS class identifiers (QCI) values for each E-RAB associated with the S1-AP session;

analyze S1-AP signaling cause codes associated with the one or more identified dropped calls to identify one or more call drop reasons; and

generate an Adaptive Session Intelligence (ASI) data set based on the combined analysis of the S1-AP signaling messages, one or more QCI values and of the S1-AP signaling cause codes, wherein the ASI data set includes one or more metrics indicative of E-RAB status at different stages of a corresponding live call.

8. The network device of claim 7, wherein the call tracking engine configured to analyze the S1-AP signaling messages is further configured to partition the E-RAB QCI values into a plurality of groups.

9. The network device of claim 8, wherein the call tracking engine configured to analyze the S1-AP signaling messages exchanged between the eNodeB and the MME is further configured to analyze at least one of the following messages:

INITIAL CONTEXT SETUP RESPONSE, INITIAL CONTEXT SETUP FAILURE, E-RAB SETUP RESPONSE, UE CONTEXT MODIFICATION FAILURE, E-RAB MODIFY RESPONSE, HANDOVER REQUEST ACKNOWLEDGE, HANDOVER PREPARATION FAILURE, HANDOVER COMMAND, HANDOVER FAILURE, PATH SWITCH REQUEST ACKNOWLEDGE, PATH SWITCH REQUEST FAILURE, E-RAB RELEASE COMMAND, E-RAB RELEASE RESPONSE, E-RAB RELEASE INDICATION and UE CONTEXT RELEASE REQUEST.

10. The network device of claim 8, wherein the call tracking engine configured to analyze the S1-AP signaling messages is further configured to track a plurality of S1-AP attributes comprising International Mobile Subscriber Identity (IMSI), cell Id, International Mobile Equipment Identity (IMEI), Tracking Area Identity (TAI) and E-NodeB identity.