JP3960268B2 - Path bandwidth setting method and system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a path bandwidth setting method and system, and in particular, a path bandwidth for automatically setting an MPLS path for VoIP when accommodating VoIP (Voice Over Internet Protocol) traffic in an MPLS (Multi Protocol Label Switching) network. The present invention relates to a setting method and a system.
[0002]
[Prior art]
Conventionally, there is no mechanism for automatically designing the capacity of a VoIP MPLS path, and the path capacity is designed and set manually.
[0003]
[Problems to be solved by the invention]
When the VoIP service is applied to a large-scale network, it is assumed that the traffic fluctuation of the VoIP traffic becomes large. In this case, manually changing the MPLS path capacity accommodating VoIP traffic in conjunction with frequent traffic fluctuations does not scale as an operation.
[0004]
The present invention has been made in view of the above points, and an object of the present invention is to provide a path bandwidth setting method and system capable of changing the path capacity while automatically satisfying the VoIP call loss rate performance in accordance with the changing VoIP traffic. And
[0005]
[Means for Solving the Problems]
FIG. 1 is a diagram for explaining the principle of the present invention.
[0006]
The present invention relates to a path bandwidth setting method for setting an MPLS path for VoIP when accommodating a VoIP connection in a label switching path in an MPLS network.
A call that determines the path usage capacity after permitting a call connection when a connection connection request is made. If the usage capacity exceeds the path capacity, the connection connection is rejected, and if the usage capacity is less than the capacity, the connection is permitted. The agent communicates with the network management agent that controls the path capacity of the label switching path (step 1).
In the network management agent, the call loss rate performance is monitored (step 2). The number of VoIP connection calls, the number of connection connections allowed and the number of connection connection rejections within a unit time are recorded, and the call loss rate is calculated from the recorded information (step 3).
When the call loss rate measured and calculated by the currently set label switch path in the network management agent falls into a quality degradation state for a certain period of time, or falls into an excessive quality state for a certain period of time Then, the network management agent determines the call loss rate of the path capacity that is virtually measured separately (step 4), specifies the optimal virtual path capacity that satisfies the target call loss rate characteristics (step 5), and
The network management agent transmits a path bandwidth change request to the edge label switch router of the label switching network managed by the network management agent with the specified virtual path capacity (step 6).
The edge label switch router sets a new path while sharing network resources with the path currently set by the “Make Before Break” function defined in the RSVP-TE protocol (step 7). The traffic is seamlessly transferred from the existing path to the newly set path (step 8), and the existing path is removed after the traffic shift (step 9).
[0007]
Further, the present invention provides a network management agent that performs call loss rate calculation.
In addition to the existing label switching path capacity, a virtual path in which the path capacity is virtually increased or decreased is set, and the call loss rate when the virtual path is used is also calculated.
[0008]
FIG. 2 is a principle configuration diagram of the present invention.
[0009]
The present invention relates to a call agent 40, a network management agent 50, an edge label switch router 10, and a plurality of nodes for setting up an MPLS path 30 for VoIP when accommodating a VoIP connection in a label switching path in an MPLS network. A path bandwidth setting system connected to an MPLS network,
The call agent 40
Capacity determination means 41 for determining a path usage capacity after permitting a call connection at the time of a connection connection request;
A connection permission control means for rejecting connection connection when the used capacity exceeds the path capacity, and permitting connection connection when the used capacity is less than the capacity;
First communication means 43 for communicating with the network management agent 50 for controlling the path capacity of the label switching path;
Have
The network management agent 50
A second communication means 51 for communicating with the call agent;
A call loss rate calculation means 52 for recording the number of VoIP connection calls within a unit time, the number of connection connections allowed, the number of connection connection rejections, and calculating a call loss rate from the recorded information;
In the currently set label switch path, the call loss rate measured / calculated by the call loss rate calculation means 52 falls into a quality deterioration state for a certain time, or has fallen into an excessive quality state for a certain time. In this case, a virtual path capacity specifying unit 53 that determines a call loss rate of a path capacity that is virtually measured separately and specifies an optimum virtual path capacity that satisfies the target call loss characteristic,
A third communication means 54 for transmitting a path bandwidth change request to the edge label switch router of the label switching network managed by the self-managed virtual path capacity,
The edge label switch router 10
The network is shared with the currently set path by the “Make Before Break” function defined in the RSVP-TE protocol, and a new path is set. After setting the new path, traffic is seamlessly transferred from the existing path to the newly set path. And a path setting means 11 for removing the existing path after the traffic shift.
[0010]
Further, the call loss rate calculation means 52 of the present invention includes:
When calculating the call loss rate,
In addition to the existing label switching path capacity, a virtual path in which the path capacity is virtually increased / decreased is set, and a call loss rate when the virtual path is used is also calculated.
[0011]
As described above, the present invention cooperates with a call agent and a network management agent that monitors a path capacity to reject a connection connection request that exceeds the path capacity, and performs connection permission in a state that does not exceed the capacity when the connection is established. Is possible.
[0012]
In addition, the network management agent can observe the call loss rate performance in the path, monitor the deterioration of the call loss rate performance and the excessive quality state, and estimate the optimum call loss rate characteristic.
[0013]
Furthermore, the path capacity can be changed with the estimated path capacity without interfering with the existing traffic transfer.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0015]
FIG. 3 shows a network model in one embodiment of the present invention. Since the present invention is applied to a VoIP network, a VoIP terminal 10, an edge router that accommodates an existing PSTN terminal, and a media gateway (MG) 20 exist at the network edge. At the network edge, an LSP for transferring VoIP traffic can be set in the core network. It is assumed that the VoIP packet converted by the VoIP terminal 10 and the MG 20 is transferred through the MPLS path 30 in the core network.
[0016]
In addition, VoIP call control is based on SIP (Session Initiation), H.264. It is assumed that the call agent 40 is realized by a protocol such as H.323, and not only handles call control signals between terminals but also handles bit rate information of the VoIP stream. As shown in FIG. 4, the call agent 40 includes a call admission determination unit 41, a call control unit 42, and a communication unit 43. The call admission determination unit 41 and the communication unit 43 control the MPLS path capacity. A mechanism for notifying the network manager 50 of connection information is provided.
[0017]
FIG. 5 is a diagram for explaining the operation of the VoIP call admission determination unit of the call agent according to the embodiment of the present invention. In the present invention, when the VoIP call connection request reaches the call agent 40 (step 101), the call agent 40 determines the stream capacity of the VoIP call: Δ (Δ is a band) (step 102). After judging the capacity, the connection bandwidth: X + Δ at the time of call connection is predicted from the preset path usage capacity: X information, and this value is compared with the path capacity: C. If X + Δ <C, the VoIP call is connected. (Step 103), if not, the connection of the VoIP call is rejected (Step 104). At this time, the call connection information is transferred to the network manager agent 50.
[0018]
FIG. 6 shows the configuration of the network manager agent in one embodiment of the present invention. The network manager agent 50 has connection statistical information in the statistical information storage unit 55, and the call loss rate calculation unit 52 totals the number of calls, the number of connections A, and the number of rejections B for each VoIP type as shown in FIG.
[0019]
FIG. 8 is a diagram showing the VoIP accommodation path bandwidth change history in one embodiment of the present invention, in which the call loss rate information accumulated by the network manager agent 50 is shown on the vertical axis, and the time axis is shown on the horizontal axis. The call loss rate calculation unit 52 of the network manager agent 50 calculates the call loss rate per unit time as log information from the above information and stores it in the call loss rate log information storage unit 57. At this time, in order to satisfy the communication quality of the VoIP traffic, the network manager agent 50 sets a target call loss rate (for example, B = 0.01) and a quality deterioration call loss rate (for example, which defines the quality deterioration condition of the VoIP traffic). B = 0.1), an excessive quality call loss rate that defines an excessive quality state (example: B = 0.00001). At this time, the call loss rate to be measured is
When the quality degradation state continuation time> degradation threshold time is satisfied and the degradation quality state continues for a certain time, the virtual path capacity specifying unit 53 of the network manager agent 50 increases the path capacity of the VoIP path via the communication unit 51. Activate.
[0020]
The call loss rate to be measured is
If the over-quality time> the over-threshold time, and the over-quality state continues for a certain time, the network manager agent 50 activates the VoIP path capacity reduction process via the communication unit 51.
[0021]
Next, the operation of the virtual path capacity specifying unit 53 when the increase / decrease process is activated from the call loss rate calculation unit 52 of the network manager agent 50 will be described.
[0022]
FIG. 9 is a diagram for explaining the VoIP capacity estimation using the virtual capacity according to the embodiment of the present invention, in which the virtual path capacity specifying unit 53 of the network manager agent 50 changes the path capacity of the VoIP path. The outline of the change operation mechanism is shown.
[0023]
The estimated call loss rate in FIG. 10A is measured with a virtual capacity C−Δ (a plurality of Δs are prepared), and FIG. 10B shows the measured call loss rate measured with the capacity C. FIG. ) Estimated call loss rate is measured by virtual capacity C + Δ (a plurality of Δs are prepared).
[0024]
The network manager agent 50 has a virtual path capacity value after the change in advance so that the change process can be performed immediately when the path capacity change process becomes necessary. In the example of FIG. 9, two virtual paths with different bandwidths are prepared corresponding to the bandwidth increase processing, and two virtual paths with different bandwidths are prepared corresponding to the bandwidth reduction processing. The network manager agent 50 also measures / estimates the call loss rate for the prepared virtual path, totals it as log information, and stores it in the call loss rate log information storage unit 57.
[0025]
In this state, when an abnormality occurs in the measured call loss rate, an optimal path capacity that satisfies the call loss rate target is selected from the virtual paths. In the example of FIG. 9, since the deterioration of the measured call loss rate in which the bandwidth shortage has occurred continues for a certain period or longer, the bandwidth increase processing is selected. At this time, since the C + Δ band increase path satisfies the target call loss rate, it is selected as the path band after the capacity change.
[0026]
FIG. 10 shows an operation sequence for changing the VoIP path capacity using the “Make Before break” function according to the embodiment of the present invention. Once the capacity change path bandwidth is determined, the network manager 50 issues a bandwidth change request condition to the edge node 10 of the path (step 201). The edge node 10 instructed to change the bandwidth operates the “Make Before Break” function of RSVP-TE, and sets a bandwidth change designation path in the requested reservation style for the same session (step 202). At this time, since the changed path is set in the shared reservation style, a new path can be set without affecting the network resources of the existing path. When the setting of the new path is successful, the edge node 10 seamlessly shifts to transfer of a new path of traffic transferred on the old path. After the traffic shift, the edge router deletes the old path by sending a “PathTear” message and simultaneously notifies the network manager 50 of the successful change of the path capacity (step 203). Receiving the notification, the network manager 50 notifies the CAC function (call admission control) of the call agent 40 of the change of the path capacity (step 204).
[0027]
With this operation, the present invention changes the path bandwidth of VoIP traffic without affecting the transfer of existing voice traffic while satisfying the target call loss rate.
[0028]
The present invention is not limited to the above-described embodiment, and various modifications and applications can be made within the scope of the claims.
[0029]
【The invention's effect】
As described above, according to the present invention, when accommodating VoIP traffic in an MPLS network, the target quality of the VoIP service can be improved without requiring manual monitoring and setting by an operator even in a large-scale network where traffic change is large. While satisfying, it is possible to automatically set the bandwidth change of the accommodation path of VoIP traffic.
[0030]
Further, since the transfer quality of existing traffic is not affected when the path bandwidth is changed, QoS does not deteriorate.
[0031]
Furthermore, since not only the path bandwidth increasing process due to quality deterioration but also the path band subtracting process at the time of excessive quality is performed together, economical operation of the VoIP network becomes possible.
[0032]
Thereby, an efficient and high-performance VoIP network can be constructed.
[Brief description of the drawings]
FIG. 1 is a diagram for explaining the principle of the present invention.
FIG. 2 is a principle configuration diagram of the present invention.
FIG. 3 is a network configuration diagram according to an embodiment of the present invention.
FIG. 4 is a configuration diagram of a call agent according to an embodiment of the present invention.
FIG. 5 is a diagram for explaining an operation of a VoIP acceptance determination unit of a call agent according to an embodiment of the present invention.
FIG. 6 is a configuration diagram of a network manager agent according to an embodiment of the present invention.
FIG. 7 is a VoIP connection capacity in an embodiment of the present invention.
FIG. 8 is a diagram showing a process of changing a VoIP accommodation path bandwidth according to an embodiment of the present invention.
FIG. 9 is a diagram showing VoIP capacity estimation using virtual capacity in an embodiment of the present invention.
FIG. 10 is a sequence of operations for changing the VoIP path capacity using the Make Before break function according to the embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Edge label switch router, VoIP terminal 20 MG / MPLS node 30 MPLS path 40 Call agent 41 Capacity determination means, call admission determination section 42 connection admission control means, call control section 43 First communication means, communication section 50 Network manager agent 51 Second communication unit, communication unit 52 Call loss rate calculation unit, call loss rate calculation unit 53 Virtual path capacity specifying unit, virtual path capacity specifying unit 54 Third communication unit 55 Statistical information storage unit 56 Call loss rate information 57 Call loss rate log information storage unit

Claims (4)

In a multi-protocol label switching (MPLS) network, a path bandwidth setting method for setting an MPLS path for VoIP when accommodating a VoIP (Voice Over Internet Protocol) connection in a label switching path,
A call that determines the path usage capacity after permitting a call connection when a connection connection request is made. If the usage capacity exceeds the path capacity, the connection connection is rejected, and if the usage capacity is less than the capacity, the connection is permitted. The agent communicates with the network management agent that controls the path capacity of the label switching path.
In the network management agent, the call loss rate performance is monitored, the number of VoIP connection calls per unit time, the connection connection permission number, the connection connection rejection number are recorded, and the call loss rate is calculated from the recorded information.
In the network management agent, the call loss rate measured / calculated with the currently set label switch path has fallen into a quality degradation state for a certain period of time, or has fallen into an excessive quality state for a certain period of time. In this case, the network management agent determines the call loss rate of the path capacity that is virtually measured separately, identifies the optimal virtual path capacity that satisfies the target call loss rate characteristics,
The network management agent transmits a path bandwidth change request to the edge label switch router of the label switching network managed by the network management agent with the specified virtual path capacity,
The edge label switch router sets a new path while sharing network resources with the path currently set by the “Make Before Break” function defined in RSVP-TE (Resource ReServation Protocol Traffic Engineering) protocol. A path bandwidth setting method characterized by seamlessly transferring traffic from an existing path to a newly set path after setting a new path, and further removing the existing path after the traffic shift. When the network management agent performs the call loss rate calculation,
2. The path bandwidth setting method according to claim 1, wherein in addition to the existing label switching path capacity, a virtual path in which the path capacity is virtually increased or decreased is set, and a call loss rate when the virtual path is used is also calculated. In a multi-protocol label switching (MPLS) network, when a VoIP (Voice Over Internet Protocol) connection is accommodated in a label switching path, a call agent for setting an MPLS path for VoIP, a network management agent, an edge label switch router, A path bandwidth setting system in which a plurality of nodes are connected to the MPLS network,
The call agent is
Capacity determination means for determining the path usage capacity after permitting a call connection at the time of a connection connection request;
When the used capacity is greater than the path capacity, the connection is rejected, and when the used capacity is less than the capacity, the connection permission control means for permitting the connection and the network for controlling the path capacity of the label switching path A first communication means for communicating with the management agent;
Have
The network management agent is:
A second communication means for communicating with the call agent;
A call loss rate calculating means for recording the number of VoIP connection calls within a unit time, the connection connection permission number, the connection connection rejection number, and calculating a call loss rate from the recorded information;
In the currently set label switch path, when the call loss rate measured / calculated by the call loss rate calculation means falls into a quality degradation state for a certain period of time, or falls into an excessive quality state for a certain period of time. In this case, a virtual path capacity specifying unit that determines a call loss rate of a path capacity that is virtually measured separately and specifies an optimal virtual path capacity that satisfies the target call loss rate characteristics;
A third communication means for transmitting a path bandwidth change request to the edge label switch router of the label switching network managed by itself with the identified virtual path capacity;
The edge label switch router is
A new path is set while sharing network resources with the path currently set by the “Make Before Break” function defined in the RSVP-TE (Resource ReServation Protocol Traffic Engineering) protocol. A path bandwidth setting system characterized by comprising path setting means for seamlessly shifting traffic to a newly set path and further removing the existing path after the traffic shift. The call loss rate calculating means includes:
When performing the call loss rate calculation,
4. The path bandwidth setting according to claim 3, further comprising means for setting a virtual path in which the path capacity is virtually increased / decreased in addition to the existing label switching path capacity and calculating a call loss rate when the virtual path is used. system.

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