Method For Detecting QOS
A method for detecting QoS, including: obtaining information in packets transferred between MGWs, and obtaining packet loss ratio, jitter and delay of each channel of users in an office direction in communication with the MGWs through the obtained information; obtaining average packet loss ratio, average delay and average jitter of the office direction according to the packet loss ratio, the jitter and the delay of each channel of users; and obtaining overall QoS of the office direction according to the average packet loss ratio, the average delay and the average jitter of the office direction as well as the weight coefficient of the foregoing three indices affecting the voice quality.
1 . A method for detecting QoS, comprising:
obtaining information in packets transferred between MGWs, and obtaining packet loss ratio, jitter and delay of each channel of users in an office direction in communication with the MGWs through the obtained information;
obtaining average packet loss ratio, average delay and average jitter of the office direction according to the packet loss ratio, the jitter and the delay of each channel of users; and
obtaining overall QoS of the office direction according to the average packet loss ratio, the average delay and the average jitter of the office direction as well as the weight coefficient of the foregoing three indices affecting the voice quality.
2 . The method of claim 1 , wherein the packet loss ratio is obtained in the following way:
the quantity of packets that should be received in the statistic period deducts the quantity of packets actually received in the statistic period, and then the quantity after deduction is divided by the quantity of packets that should be received in the statistic period.
3 . The method of claim 2 , wherein the quantity of packets that should be received in the statistic period is obtained in the following way: the maximum packet serial number in the statistic period deducts the maximum packet serial number in the previous statistic period.
4 . The method of claim 1 , wherein the delay is calculated according to the following formula:
Delay=( T 4 −T 1)−( T 3 −T 2)
wherein T1 is the time when a first MGW sends a packet; T2 is the time when a second MGW receives the packet; T3 is the time when the second MGW sends a packet; T4 is the time when the first MGW receives the packet.
5 . The method of claim 4 , wherein the jitter is obtained according to the change of delay.
6 . The method of claim 1 , wherein the process of obtaining information in the packet transferred between MGWs, and obtaining the packet loss ratio, the jitter and the delay of each channel of users in the office direction in communication with the MGWs through the obtained information comprises:
sending, by a first MGW, packets which indicate each channel of users in the specified office direction in communication with the first MGW to a second MGW through an IP bearer network, in which the packets carry the users' local time and serial numbers;
obtaining, by the second MGW, the users' packet loss ratio according to the recorded serial number and the received packets, upon receiving the packets sent by the first MGW;
sending, by the second MGW, packets which indicate each channel of users in the specified office direction in communication with the second MGW to the first MGW through the IP bearer network, in which the packets carry local time and serial number of the second MGW, the time of receiving the packets from the first MGW, and the obtained users' packet loss ratio; and
by the first MGW, obtaining the users' packet loss ratio, and calculating the delay and the jitter according to the local time of receiving the packets and timestamp carried in the packets, upon receiving the packets sent by the second MGW.
7 . The method of claim 6 , wherein the packet loss ratio is obtained in the following way:
the quantity of packets that should be received in the statistic period deducts the quantity of packets actually received in the statistic period, and then the quantity after deduction is divided by the quantity of packets that should be received in the statistic period.
8 . The method of claim 7 , wherein the quantity of packets that should be received in the statistic period is obtained in the following way: the maximum packet serial number in the statistic period deducts the maximum packet serial number in the previous statistic period.
9 . The method of claim 6 , wherein the delay is calculated according to the following formula:
Delay=( T 4 −T 1)−( T 3 −T 2)
wherein T1 is the time when a first MGW sends a packet; T2 is the time when a second MGW receives the packet; T3 is the time when the second MGW sends a packet; T4 is the time when the first MGW receives the packet.
10 . The method of claim 9 , wherein the jitter is obtained according to the change of delay.
11 . The method of claim 1 , wherein the average packet loss ratio, the average delay and the average jitter are calculated according to the following formulas:
average
packet
loss
ratio
in
the
specified
office
direction
=
∑
0
user
quantity
in
specified
office
direction
packet
loss
ratio
of
each
user
;
average
delay
in
the
specified
office
direction
=
∑
0
user
quantity
in
specified
office
direction
delay
of
each
user
;
and
average
jitter
in
the
specified
office
direction
=
∑
0
user
quantity
in
specified
office
direction
jitter
of
each
user
.
12 . The method of claim 1 , wherein the packet is a Real-time Transfer Control Protocol, RTCP, packet.
13 . The method of claim 1 , wherein the packet is sent periodically.
14 . A system for detecting QoS, comprising:
means for obtaining information in packets transferred between MGWs, and obtaining packet loss ratio, jitter and delay of each channel of users in an office direction in communication with the MGWs through the obtained information;
means for obtaining average packet loss ratio, average delay and average jitter of the office direction according to the packet loss ratio, the jitter and the delay of each channel of users; and
means for obtaining overall QoS of the office direction according to the average packet loss ratio, the average delay and the average jitter of the office direction as well as the weight coefficient of the foregoing three indices affecting the voice quality.
15 . The system of claim 14 , wherein means for obtaining information in the packets transferred between MGWs, and obtaining the packet loss ratio, the jitter and the delay of each channel of users in the office direction in communication with the MGWs through the obtained information comprises:
a first MGW, configured to send packets which indicate each channel of users in the specified office direction in communication with the first MGW to a second MGW through an IP bearer network, in which the packets carry the users' local time and serial numbers, receive the packets sent by the second MGW, obtain the users' packet loss ratio, and calculate the delay and jitter according to the local time of receiving the packets and the timestamp carried in the packets;
a second MGW, configured to receive the packets sent by the first MGW and obtain the users' packet loss ratio according to the recorded serial number and the received packets, and send packets which indicate each channel of users in the specified office direction in communication with the second MGW to the first MGW through the IP bearer network, in which the packets carry local time and serial number of the second MGW, the time of receiving the packets from the first MGW, and the obtained users' packet loss ratio.