PACKET ANALYSIS APPARATUS AND METHOD THEREOF

• US 20100322095A1
• Filed: 06/14/2010
• Published: 12/23/2010
• Est. Priority Date: 06/19/2009
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Miyazaki, Hideaki, Morinaga, Masanobu, Fukuyama, Noriyuki, OKADA, Sumiyo
• Granted Patent: US 8,649,283 B2
• Time in Patent Office: Days
• US Class Current: 370/252
• CPC Class Codes: H04L 43/0835 One way packet loss
• CPC Class Codes: H04L 65/65 Network streaming protocols, e.g. real-time transport protocol [RTP] or real-time control protocol [RTCP]

Abstract

A method executed by a packet analysis apparatus for analyzing packets including voice packets and non-voice packets includes: capturing packets in a specific session; storing the captured packets in a storage; screening the stored packets to count up a receipt count of voice packets; determining whether packet loss has occurred in the specific session; and determining whether loss packets are voice packets in accordance with received packets adjacent to the loss packets to count up a loss count of voice packets when the packet loss has occurred.

Claims

1. A method executed by a packet analysis apparatus for analyzing packets including voice packets and non-voice packets, the method comprising:

capturing packets in a specific session;

storing the captured packets in a storage;

screening the stored packets to count up a receipt count of voice packets;

determining whether packet loss has occurred in the specific session; and

determining, by the packet analysis apparatus, whether loss packets are voice packets in accordance with received packets adjacent to the loss packets to count up a loss count of voice packets when the packet loss has occurred.

2. The method according to claim 1, wherein

the packet analysis apparatus screens the stored packets in accordance with predefined characteristics of non-voice packets.

3. The method according to claim 2, wherein

the non-voice packets are dual tone multiple frequency (DTMF) packets of a DTMF event, and

the predefined characteristics of non-voice packets include at least one of a retransmission count of the DTMF event, a duration of each DTMF packet, and a transmission interval of the DTMF packets,

the retransmission count representing how many times a terminal packet has been retransmitted, the terminal packet being a DTMF packet transmitted as a last packet of the DTMF event,

the duration being represented by a time stamp since a start time of the DTMF event,

the transmission interval being an interval of transmissions of packets.

4. The method according to claim 3, further comprising:

determining whether the loss packets are succeeded by a retransmitted packet of the terminal packet or by DTMF packets including the retransmitted packet of the terminal packet;

calculating a total count of packets from a lead packet to the terminal packet of the DTMF event including the retransmitted packet by dividing a duration included in the retransmitted packet by a transmission interval of the DTMF packets when the loss packets are succeeded by the retransmitted packet of the terminal packet or by DTMF packets including the retransmitted packet of the terminal packet; and

determining whether the loss packets are voice packets or DTMF packets in accordance with

an amount of DTMF packets succeeding the loss packets,

the retransmission count of the terminal packet, and

the total count of packets from the lead packet to the terminal packet of the DTMF event.

5. The method according to claim 3, further comprising:

determining whether the loss packets are preceded by a retransmitted packet of the terminal packet; and

determining whether the loss packets are voice packets or DTMF packets in accordance with

a location of the terminal packet and

the retransmission count of the terminal packet

when the loss packets are preceded by a retransmitted packet of the terminal packet,

the location of the terminal packet being determined in accordance with a duration included in the retransmitted packet.

6. The method according to claim 3, further comprising:

determining whether the loss packets are preceded by a DTMF packet other than a retransmitted packet of the terminal packet and succeeded by a voice packet; and

determining, when the loss packets are preceded by a DTMF packet other than the retransmitted packet of the terminal packet and succeeded by a voice packet, that a loss count of DTMF packets is more than or equals to the retransmission count.

7. The method according to claim 3, further comprising:

calculating a transmission interval of loss packets in accordance with a difference in time and a sequence number between previous and next packets to the loss packets;

determining whether a first condition has been satisfied, the first condition being that the transmission interval of loss packets is identical with a transmission interval of voice packets and is not identical with a transmission interval of DTMF packets;

determining that the loss packets are voice packets when the first condition has been satisfied;

determining whether a second condition has been satisfied, the second condition being that the transmission interval of loss packets is not identical with the transmission interval of voice packets and is identical with the transmission interval of DTMF packets; and

determining that the loss packets are DTMF packets when the second condition has been satisfied.

8. The method according to claim 3, further comprising:

obtaining a solution of a set of simultaneous equations when a transmission interval of voice packets differs from a transmission interval of DTMF packets, the set of simultaneous equations having as variables an amount of voice packets and an amount of non-voice packets out of packets to be calculated, the packets to be calculated including the loss packets and a packet that succeeds the loss packets; and

calculating the loss count of voice packets and a loss count of DTMF packets in accordance with the solution of the set of simultaneous equations.

9. The method according to claim 1, further comprising:

determining whether both of previous and next packets to the loss packets are voice packets;

determining that the loss packets are voice packets when both of the previous and next packets to the loss packets are voice packets;

determining whether both of the previous and next packets to the loss packets are non-voice packets; and

determining that the loss packets are non-voice packets when both of the previous and next packets to the loss packets are non-voice packets.

10. The method according to claim 1, further comprising:

counting up a receipt count of non-voice packets; and

counting up a loss count of non-voice packets.

11. A computer-readable medium storing a program causing a computer for analyzing packets including voice packets and non-voice packets to execute:

capturing packets in a specific session;

storing the captured packets in a storage;

screening the stored packets to count up a receipt count of voice packets;

determining whether packet loss has occurred in the specific session; and

determining whether loss packets are voice packets in accordance with received packets adjacent to the loss packets to count up a loss count of voice packets when the packet loss has occurred.

12. A packet analysis apparatus for analyzing packets including voice packets and non-voice packets, the packet analysis apparatus comprising:

a packet captor configured to capture packets in a specific session to store the captured packets in a storage;

a voice packet screener configured to screen the stored packets to count up a receipt count of voice packets; and

a loss packet estimator configured to

determine whether packet loss has occurred in the specific session, and

determine whether loss packets are voice packets in accordance with received packets adjacent to the loss packets to count up a loss count of voice packets when the packet loss has occurred.