Title of Invention	METHOD AND APPARATUS FOR ASSIGNING TRANSCODING RESOURCES IN A SESSION BOARDER CONTROLLER
Abstract	Method and Apparatus for Assigning Transcoding Resources in a Session Boarder Controller A session boarder controller (4, 5; 20) is use between peering networks (1, 2, 3) supporting packefized voice transport. In order to save expensive DSP resources, a dynamic transcoder resource management is proposed, The session boarder controller contains; - I/O means [21, 22) having an I/O capacity that corresponds to at (east a predefined number of trunks; - digital signal processing means (23a, 23b, 23c) adapted to convert between different type of voice codec’s used for packetized voice transport in incoming or outgoing connections, said digital signal processing means (23a, 23b, 23c) having limited processing capacity; and control means (24) adopted to determine idle processing capacity of said digital signal processing means (23a, 23b, 23c} and to reject resource-consuming connections that require codec conversion, if the total amount of idle processing capacity would fall below a threshold that depends on the number of idle trunks. (Figure 2)

Title of Invention

METHOD AND APPARATUS FOR ASSIGNING TRANSCODING RESOURCES IN A SESSION BOARDER CONTROLLER

Abstract

Method and Apparatus for Assigning Transcoding Resources in a Session Boarder Controller A session boarder controller (4, 5; 20) is use between peering networks (1, 2, 3) supporting packefized voice transport. In order to save expensive DSP resources, a dynamic transcoder resource management is proposed, The session boarder controller contains; - I/O means [21, 22) having an I/O capacity that corresponds to at (east a predefined number of trunks; - digital signal processing means (23a, 23b, 23c) adapted to convert between different type of voice codec’s used for packetized voice transport in incoming or outgoing connections, said digital signal processing means (23a, 23b, 23c) having limited processing capacity; and control means (24) adopted to determine idle processing capacity of said digital signal processing means (23a, 23b, 23c} and to reject resource-consuming connections that require codec conversion, if the total amount of idle processing capacity would fall below a threshold that depends on the number of idle trunks. (Figure 2)

Full Text	Method and Apparatus for Assigning Transcoding Resources in a Session Boarder Controller Field of the Invention The present invention relates to the field of telecommunications and more particularly to a method and ralated apparatus for assigning transcoding resources in a session boarder controller of a next generation network. Background of the Invention The telecommunications industry is currently undergoing a transformation from a traditional circuit switched network; which was originally designed and optimized for carrying voice lelepliony traffic, to packet based networks which will be capable of efficiently supporting both voice and data communications. A next generation network (NGN) is o packet-based network that employs new control, management, and signaling techniques to provide both narrow-band voice telephony services and broadband multimedia services, NGNs have been described in several standardization bodies, defining network models and an architecture of the new network. These standordizotion bodies include 3GPP with IMS (IP Multimedia Subsystem), ETSI with TISPAN (Telecoms & Internet Converged Services & Protocols for Advanced Networks) and MPS who are defining the architectural aspects. The general idea behind NGN is that all information is transmitted via j packets, which are labeled according to their type (data, voice, etc) and handled differently for Quality of Service (QoS) and security purposes by traffic management equipment. Media gateways are devices, which are used at the boarder between an NGN and a PSTN [public switched telephone network}. ) In next generation networking, different protocols for voice transmission are in use today. These include G711, G729, G723, G726, and AMR (Adaptive Multi-Rate} and all use different voice codecs. At the interconnection point between different NGNs, goteways are hence required which perform transcoding to convert between different protocols used in the peering I The conversion as such Is typically carried out with the aid of Digital Signal Processors (DSPs). A DSP Is a specialized microprocessor specifically designed for real-time digital signal processing. DSPs are however relatively expensive and will considerably increase the price of the media gateways. It is hence desirable to utilize DSP resources economically. Today, existing gateways do either perform 100 % transcoding as for example between mobile and fixed networks and are hence equipped with full 100 % DSP capocity, or do not perform transcoding at oil. It might be desirable to provide a medio session boarder controller with less than 100 % transcoding capabilities, This con however lead to a situation where idle links are blocked when all installed DSP capacity is busy. In this cose, no further service will be possible anymore, even service that would not require transcoding. This con be unacceptable in certain coses where for example peering network providers or customers have configured a number of links but the DSP resources are not able to process the amount of parallel sessions. It is therefore an object of the present invention to provide a method and related media session boarder controller for a next generation network which does not require 100 % transcoding resources but which avoids situations in which further service is blocked because of exhausted DSP resources. Summary of the Invention These and other objects ihot appear below are achieved by a session boarder controller with dynamic transcoder resource management. In particulor for assigning transcoding resources in a session boarder controller (he invention proposes the steps of: determining for an incoming coll whether transcoding is required determining an amount of idle transcoding resources in said session boarder controller; determining a threshold value that depends on the number of idle trunks supported fay said session boarder controller; and assigning transcoding resources to said incoming call if a remaining amount of idle transcoding resources is greater than said threshold value and rejecting said call otherwise, The session boarder controller according to the invention contains: I/O means having an I/O copacity that corresponds to at least a predefined number of trunks; digital signal processing means adapted to convert between different type of voice codecs used for packetized voice transport in incoming or outgoing connections, said digital signal processing means having limited processing capacity; and control means adapted to determine idle processing capacity of said digital signal processing means and to reject resource-consuming connections that require codec conversion, if the total amount of idle processing capacity would fall balow a threshold that depends on the number of idle trunks. With this transcoder resource management function, the network tronscoder resources can not be overbooked. This will prevent the network from blocking due to 0 lack of resources. The dynamic transcoding management will lead to satisfied customers, knov/ing how to configure network interfaces with transcoding and what fo negotiate with peering paitners. The invention also provides significant odvantages for reducing equipmenl costs for the expensive DSP resources. Brief Description of ths Drawings Preferred embodiments of the present invention will now be described with reference to the accompanying drawings in which figure 1 shows an example next generation network where transcoding will be required; figure 2 shows a block diagram of a session boarder controller; and figure 3 shows a flow chart of the resource management function. Detailed Description of the Invention A simplified network in which the invention can be applied is shown schematically in figure 1. A first carrier network 1 and a second carrier network 2 are interconnected through a third network 3. All three networks are next generation networks and support packetized transport of voice services using voice over IP (VoIP) technology or any other suitable packet format. For the purpose of the present invention, the focus is on the functionality and abilities of network 3, which might be for example a backbone network of a i; nationol operotor, while carrier networks 1 and 2 can be for example metro networks of local operators, so called Other Licensed Operators (OLOs), or private company networks. A first medio session boarder controller 4 connects network 1 to network 3 and a second medio session boarder controller 5 connects network 2 to network 3. Signaling messages are routed to o signaling session boarder controller 6 in network 3, Signaling session boarder controllers are sometimes also referred to as softswJtchas. The signaling session boarder controller 6 selects a path for a connection to be established through network 3 and configures the media session boarder controllers 4 and 5 and other involved devices such as routers and switches along the selected path. A suitable protocol for the transport of voice services through IP networks is for exomple the Reol-Time Transport Protocol (RTP). Suitable signaling protocols that con be used for the communication with the signaling session boarder controller 6 include for example Megoco and SIP. In order to transmit onalog voice over a digital network the voice signal needs to be encoded into a data stream. Conversely, a corresponding decoding is necessary at the receiver side. This encoding and decoding process is referred to as codec. Sometimes the term codes is also used for device or algorithm that performs this encoding/decoding. As mentionad above, a number of different codecs are in use today for digital telephony. The predominant codec in public switched telephone networks [PSTNs] is G71 1 but a voiiety of different codecs are in use for mobile communication and VoIP services in public and private networks. According to the present invention, the medio session boarder controllers 4 and 5 support at their interfaces 7 and 8 towards the customer networks 1 and 2 a set of different voice codecs, respectively. In the preferred embodiment, at least the codecs G711, G729, and G723 ore supported. Gateways 4 and 5 are hence equipped with DSPs, which can perform the conversion between different codecs. Such conversion between different voice codecs is also termed transcoding, and it is generally known in the art how to perform real time transcending of ancodad voice data streams. The goteways 4 and 5 are equipped with less than 100 % DSP resources, In other words, they have less DSP resources than would be necessary to perform transcoding on all voice calls the gateway is able to handle at the same time. The present invention hence proposes to introduce a control instance that keeps track of the DSP resources in a gateway and refuses resource-consuming connections thot require transcoding, while preserving resources for less resource-consuming connections, A block diagram of a media session boarder controller is shown in figure 2. The session boarder controller 20 has first interface 21 and a second interface 22 for connecting to a first and second network, respectively. These interfaces can for example be Gigobit Ethernet interfaces and can receive and transmit dato traffic including hundreds of voice calls at a time as well as other type of media like video and multimedia. A number of DSPs 23a, 23b, 23c ore connected between the two interfaces 21, 22, The DSPs operate in parallel and are controlled by a controller 24. DSPs 23a, 23b, 23c are progrommed to perform transcoding as well as other signal processing functions as may be required depending on the particular media type. It should be clear that a DSP can handle multiple voice calls in parallel, though the number of calls a DSP can handle depends on the transcoding operations it needs to carry out in each case. The embodiment shows three DSPs operating in parallel on the received and transmitted data streams. These represent the available DSP resources. Controller 24 keeps track of the DSP resources and organi2es which DSP handles which voice coll. It should be clear that the invention is not restricted to the use of three DSPs but con be carried out with a much higher number or even just with a single DSP. Since the session boarder controller 20 has less DSP resources than would be required to perform transcoding on the maximum number of calls in parallel, the controller 24 provides dynamic resource management and refuses resource-consuming connections thot require tronscoding, if the total amount of idle processing copacify would fall below o certain threshold. This threshold is dynamic and depends on the number of calls sarvad at the moment. At times when more colls ore served by the gateway 20 and hence less free line capacity is available for further calls, the DSPs are certainly more busy and the threshold is hence set lower than at times when less calls are served. In the preferred embodiment, two parameters are introduced; 1) the number trunks connected and 2) a measure for DSP resources, which is called "credits" hereinafter. Each codec represents a certain predefined amount of credits It consumes when executed and each established connection reduces the total amount of idle DSP resources by the amount of credits that correspond to the codec used for this connection. Connections ore refused If the total amount of idle resources would fall below a threshold that depends on the number of idle trunks. In the embodiment, the media session boarder controller supports the codecs G711, G729, ond G723. G711 corresponds to 1 credit; G729 corresponds to 3 credits and G723 corresponds to 4 credits. It is assumed that the medio session boarder controller is configured for 1 000 trunks and that it has DSP resources corresponding to in total 1500 credits. Such figures can for example be agreed in a contract between the operators of the peering gateways and the media session boarder controller is hence dimensioned accordingly. The rule according to which the controller assigns DSP resources and rejects connection requests is thol connections are only allowed as long as the amount of credits left is greater or equal to the amount of idie fr^Jr^ks. Under this rule, a carrier can use for example 200 connections with G729 codec. This will consume an amount of 200 ' 3 credits = 600 credits. The carrier has thus 900 credits left and 800 idle trunks. The carrier might for example try to establish 300 connections with G729 codec. This would consumn an amount of 300 * 3 credits = 900 credits. The carrier has thus 600 credits left hul 700 idle trunks. The number of idle trunks is hence higher than the nmouni of remaining credits. Since this violates the rule, the last connections witi be rejected by the controller. The same would happen if the carrier intends to establish 200 connections with G723 codec. The use of 200 channels with G723 would require 200 * 4 credits = 800 credits, which would violate the rule: 800 trunks idle versus 600 remaining credits. Trunl In such contract, also the rules according to which DSP resources are assigned and connection requests rejected con be agreed. For instance, an operator may wish to have as many connections accepted as he has credits. Under this circumstance, connections will not be refused as long as credits ore available but at the price that idle trunks cannot be used because of exhausted credits. it should be clear that the figures of credits and trunks as well as the rules are only non-limiting examples of the invention. Depending on the actual needs of the operotors, many other rules can be chosen. In a more general sense, the credit "prices" could be defined as follows: - 0 credits: transparent, media agnostic connection where both peering carriers support the same codec. Media agnostic means here no detection and processing of medio content will occur such as tone detection, comfort noise generation, fax demodulation (T,38) or the like. 1 credit: transparent, but media awore connection where both peering corriers support the same codec. DSP performs detection and/or processing functions on the media stream such as tone detection, silent suppression, comfort noise generation (voice only), fax demodulation [T.38), text over IP or others. >1 credits: transcoded connection where both peering carriers do not support the same codec, The price depends on trhe selected codec. For medio agnostic transparent connections, this would mean that such calls could be established even when no DSP resources are available any more. Another remark is that the function of controller 24 be implemented in a media session boarder controller as it is shown for the sake of simplicity. Controller 24 will then be implemented in the internal host processor of a media session boarder controller 4, 5, In an alternative embodiment, which is even preferred over the first alternative, controller functionality 24 con be implemented in a signaling session boarder controller controlling media session boarder controller 4,5, i.e. in Softswitch 6 of figure 1. Figure 3 shows a flow chort of 0 method for assigning resources in the session boarder controller 20. In step 31 □ call request for a voice coll arises. For example an end used in network 1 places a coll to an end user in network 3. Step 32 determines whether the coll coming from network 1 to gateway 7 requires transcoding. If so, step 33 determines the DSP capacity in of gatewoy 4 that will remain if gatewoy 4 serves the call. This remaining capacity is denoted with C. Step 34 determines a threshold value T, which depends on the number of idle trunks gateway 4 is designed to serve. Step 35 determines whether the remaining copacity C is greater than or equal to the threshold value T, If not, the call is rejected in step 36. If so, step 37 assigns the required DSP resources ond routes the coll through gateway 4 'into network 3. If the call requires no transcoding as determined in step 32, the call is also accepted and step 37 assigns the required DSP resources. Optionally, a further check 38 con be introduced which determines whether idle credits are available. This step is optional, since depending on the rules used to determine the threshold value T, this situation con occur or not. What is claimed is 1. A method of assigning transcoding resources in a session boarder controller (4, 5; 20} interconnecting peering packet networks (1, 2, 3) supporting packetized voice transport; the method comprising the steps of: - determining for an incoming call whether transcoding is required; and if she- determining an amount of idle transcoding resources in said session boarder controller {4, 5; 20); - determining a threshold value that depends on the number of idle trunks available at said session boarder controller (4, 5; 20); and - assigning transcoding resources to said incoming call if the amount of idle transcoding resources that will remain after resource assignment is greater than said threshold value, and rejecting said call otherwise. 2. The method of claim 1, wherein soid amount of transcoding resources Is measured in arbitrary units and wherein each codec supported by sold session boarder controller has assigned a certain amount of said units corresponding to the amount of transcoding resources it requires for processing. 3. The method of claim 1, wherein said threshold is chosen in such a way that it becomes smaller the more trunks ore busy. 4. The method of claim 1, wherein said threshold Is a linear function of the number of Idle trunks. 5. A session boarder controller (4, 5; 20} for use between peering networks [1, 2, 3) supporting packetized voice transport; said session border controller (4, 5; 20) comprising: - J/O means (21, 22) having an I/O capacity that corresponds to at least a predefined number of trunks; - digital signal processing means {23a, 23b, 23c) adapted to convert between different type of voice codecs used for packetized voice transport of in incoming or outgoing connections, said digital signal processing means (23a, 23b, 23c) having limited processing capacity; and - control means (24) adapted to determine Idle processing capacity of said digital signal processing means {23a, 23b, 23c), and if a connection to be established is a resource consuming connection that requires codec conversion to reject said connection, if the total amount of idle processing copacity that will remain offer resource assignment falls below a threshold that depends on the number of idle trunks. 6. The session boarder controller of claim 5, wherein said digital signal processing means are adapted to support at least two of the list G7l 1, G729, G723, G726, andAMR. 7. The session boarder controller of claim 5, wherein said I/O means (21, 22) and said digital signal processing means (23a, 23b, 23c) are implemented in a media session boarder controller (4, 5) and v/herein said control means (24) are implemented in o separate signaling session boarder controller (6) controlling said media session boarder controller (4, 5).

Full Text

Method and Apparatus for Assigning Transcoding Resources in a Session
Boarder Controller
Field of the Invention
The present invention relates to the field of telecommunications and more particularly to a method and ralated apparatus for assigning transcoding resources in a session boarder controller of a next generation network.
Background of the Invention
The telecommunications industry is currently undergoing a transformation from a traditional circuit switched network; which was originally designed and optimized for carrying voice lelepliony traffic, to packet based networks which will be capable of efficiently supporting both voice and data communications.
A next generation network (NGN) is o packet-based network that employs new control, management, and signaling techniques to provide both narrow-band voice telephony services and broadband multimedia services,
NGNs have been described in several standardization bodies, defining network models and an architecture of the new network. These standordizotion bodies include 3GPP with IMS (IP Multimedia Subsystem), ETSI

with TISPAN (Telecoms & Internet Converged Services & Protocols for Advanced Networks) and MPS who are defining the architectural aspects.
The general idea behind NGN is that all information is transmitted via j packets, which are labeled according to their type (data, voice, etc) and
handled differently for Quality of Service (QoS) and security purposes by traffic management equipment. Media gateways are devices, which are used at the boarder between an NGN and a PSTN [public switched telephone network}.
) In next generation networking, different protocols for voice transmission are in use today. These include G711, G729, G723, G726, and AMR (Adaptive Multi-Rate} and all use different voice codecs. At the interconnection point between different NGNs, goteways are hence required which perform transcoding to convert between different protocols used in the peering
I The conversion as such Is typically carried out with the aid of Digital Signal Processors (DSPs). A DSP Is a specialized microprocessor specifically designed for real-time digital signal processing. DSPs are however relatively expensive and will considerably increase the price of the media gateways. It is hence desirable to utilize DSP resources economically.
Today, existing gateways do either perform 100 % transcoding as for example between mobile and fixed networks and are hence equipped with full 100 % DSP capocity, or do not perform transcoding at oil.
It might be desirable to provide a medio session boarder controller with less than 100 % transcoding capabilities, This con however lead to a situation where idle links are blocked when all installed DSP capacity is busy. In this cose, no further service will be possible anymore, even service that would not require transcoding. This con be unacceptable in certain coses where for

example peering network providers or customers have configured a number of links but the DSP resources are not able to process the amount of parallel sessions.
It is therefore an object of the present invention to provide a method and related media session boarder controller for a next generation network which does not require 100 % transcoding resources but which avoids situations in which further service is blocked because of exhausted DSP resources.
Summary of the Invention
These and other objects ihot appear below are achieved by a session boarder controller with dynamic transcoder resource management.
In particulor for assigning transcoding resources in a session boarder
controller (he invention proposes the steps of:
determining for an incoming coll whether transcoding is required
determining an amount of idle transcoding resources in said session
boarder controller;
determining a threshold value that depends on the number of idle trunks
supported fay said session boarder controller; and
assigning transcoding resources to said incoming call if a remaining
amount of idle transcoding resources is greater than said threshold value
and rejecting said call otherwise,
The session boarder controller according to the invention contains: I/O means having an I/O copacity that corresponds to at least a predefined number of trunks;
digital signal processing means adapted to convert between different type of voice codecs used for packetized voice transport in incoming or outgoing connections, said digital signal processing means having limited processing capacity; and
control means adapted to determine idle processing capacity of said digital signal processing means and to reject resource-consuming

connections that require codec conversion, if the total amount of idle processing capacity would fall balow a threshold that depends on the number of idle trunks.
With this transcoder resource management function, the network tronscoder resources can not be overbooked. This will prevent the network from blocking due to 0 lack of resources.
The dynamic transcoding management will lead to satisfied customers, knov/ing how to configure network interfaces with transcoding and what fo negotiate with peering paitners. The invention also provides significant odvantages for reducing equipmenl costs for the expensive DSP resources.
Brief Description of ths Drawings
Preferred embodiments of the present invention will now be described with reference to the accompanying drawings in which
figure 1 shows an example next generation network where transcoding will be required;
figure 2 shows a block diagram of a session boarder controller; and
figure 3 shows a flow chart of the resource management function.
Detailed Description of the Invention
A simplified network in which the invention can be applied is shown schematically in figure 1. A first carrier network 1 and a second carrier network 2 are interconnected through a third network 3. All three networks are next generation networks and support packetized transport of voice services using voice over IP (VoIP) technology or any other suitable packet format.
For the purpose of the present invention, the focus is on the functionality and abilities of network 3, which might be for example a backbone network of a
i;

nationol operotor, while carrier networks 1 and 2 can be for example metro networks of local operators, so called Other Licensed Operators (OLOs), or private company networks.
A first medio session boarder controller 4 connects network 1 to network 3 and a second medio session boarder controller 5 connects network 2 to network 3. Signaling messages are routed to o signaling session boarder controller 6 in network 3, Signaling session boarder controllers are sometimes also referred to as softswJtchas. The signaling session boarder controller 6 selects a path for a connection to be established through network 3 and configures the media session boarder controllers 4 and 5 and other involved devices such as routers and switches along the selected path.
A suitable protocol for the transport of voice services through IP networks is for exomple the Reol-Time Transport Protocol (RTP). Suitable signaling protocols that con be used for the communication with the signaling session boarder controller 6 include for example Megoco and SIP.
In order to transmit onalog voice over a digital network the voice signal needs to be encoded into a data stream. Conversely, a corresponding decoding is necessary at the receiver side. This encoding and decoding process is referred to as codec. Sometimes the term codes is also used for device or algorithm that performs this encoding/decoding.
As mentionad above, a number of different codecs are in use today for digital telephony. The predominant codec in public switched telephone networks [PSTNs] is G71 1 but a voiiety of different codecs are in use for mobile communication and VoIP services in public and private networks.
According to the present invention, the medio session boarder controllers 4 and 5 support at their interfaces 7 and 8 towards the customer networks 1 and 2 a set of different voice codecs, respectively. In the preferred embodiment, at least the codecs G711, G729, and G723 ore supported.

Gateways 4 and 5 are hence equipped with DSPs, which can perform the conversion between different codecs. Such conversion between different voice codecs is also termed transcoding, and it is generally known in the art how to perform real time transcending of ancodad voice data streams.
The goteways 4 and 5 are equipped with less than 100 % DSP resources, In other words, they have less DSP resources than would be necessary to perform transcoding on all voice calls the gateway is able to handle at the same time.
The present invention hence proposes to introduce a control instance that keeps track of the DSP resources in a gateway and refuses resource-consuming connections thot require transcoding, while preserving resources for less resource-consuming connections,
A block diagram of a media session boarder controller is shown in figure 2. The session boarder controller 20 has first interface 21 and a second interface 22 for connecting to a first and second network, respectively. These interfaces can for example be Gigobit Ethernet interfaces and can receive and transmit dato traffic including hundreds of voice calls at a time as well as other type of media like video and multimedia.
A number of DSPs 23a, 23b, 23c ore connected between the two interfaces 21, 22, The DSPs operate in parallel and are controlled by a controller 24. DSPs 23a, 23b, 23c are progrommed to perform transcoding as well as other signal processing functions as may be required depending on the particular media type. It should be clear that a DSP can handle multiple voice calls in parallel, though the number of calls a DSP can handle depends on the transcoding operations it needs to carry out in each case.
The embodiment shows three DSPs operating in parallel on the received and transmitted data streams. These represent the available DSP resources. Controller 24 keeps track of the DSP resources and organi2es which DSP handles which voice coll.

It should be clear that the invention is not restricted to the use of three DSPs but con be carried out with a much higher number or even just with a single DSP.
Since the session boarder controller 20 has less DSP resources than would be required to perform transcoding on the maximum number of calls in parallel, the controller 24 provides dynamic resource management and refuses resource-consuming connections thot require tronscoding, if the total amount of idle processing copacify would fall below o certain threshold. This threshold is dynamic and depends on the number of calls sarvad at the moment. At times when more colls ore served by the gateway 20 and hence less free line capacity is available for further calls, the DSPs are certainly more busy and the threshold is hence set lower than at times when less calls are served.
In the preferred embodiment, two parameters are introduced; 1) the number trunks connected and 2) a measure for DSP resources, which is called "credits" hereinafter.
Each codec represents a certain predefined amount of credits It consumes when executed and each established connection reduces the total amount of idle DSP resources by the amount of credits that correspond to the codec used for this connection. Connections ore refused If the total amount of idle resources would fall below a threshold that depends on the number of idle trunks.
In the embodiment, the media session boarder controller supports the codecs G711, G729, ond G723. G711 corresponds to 1 credit; G729 corresponds to 3 credits and G723 corresponds to 4 credits.
It is assumed that the medio session boarder controller is configured for 1 000 trunks and that it has DSP resources corresponding to in total 1500 credits. Such figures can for example be agreed in a contract between the operators of the peering gateways and the media session boarder controller is hence dimensioned accordingly.

The rule according to which the controller assigns DSP resources and rejects connection requests is thol connections are only allowed as long as the amount of credits left is greater or equal to the amount of idie fr^Jr^ks.
Under this rule, a carrier can use for example 200 connections with G729 codec. This will consume an amount of 200 ' 3 credits = 600 credits. The carrier has thus 900 credits left and 800 idle trunks.
The carrier might for example try to establish 300 connections with G729 codec. This would consumn an amount of 300 * 3 credits = 900 credits. The carrier has thus 600 credits left hul 700 idle trunks. The number of idle trunks is hence higher than the nmouni of remaining credits. Since this violates the rule, the last connections witi be rejected by the controller.
The same would happen if the carrier intends to establish 200 connections with G723 codec. The use of 200 channels with G723 would require 200 * 4 credits = 800 credits, which would violate the rule: 800 trunks idle versus 600 remaining credits.
Trunl In such contract, also the rules according to which DSP resources are assigned and connection requests rejected con be agreed. For instance, an operator may wish to have as many connections accepted as he has credits. Under this circumstance, connections will not be refused as long as credits ore available but at the price that idle trunks cannot be used because of exhausted credits.
it should be clear that the figures of credits and trunks as well as the rules are only non-limiting examples of the invention. Depending on the actual needs of the operotors, many other rules can be chosen.

In a more general sense, the credit "prices" could be defined as follows: - 0 credits: transparent, media agnostic connection where both peering carriers support the same codec. Media agnostic means here no detection and processing of medio content will occur such as tone detection, comfort noise generation, fax demodulation (T,38) or the like. 1 credit: transparent, but media awore connection where both peering corriers support the same codec. DSP performs detection and/or processing functions on the media stream such as tone detection, silent suppression, comfort noise generation (voice only), fax demodulation [T.38), text over IP or others.
>1 credits: transcoded connection where both peering carriers do not support the same codec, The price depends on trhe selected codec.
For medio agnostic transparent connections, this would mean that such calls could be established even when no DSP resources are available any more.
Another remark is that the function of controller 24 be implemented in a media session boarder controller as it is shown for the sake of simplicity. Controller 24 will then be implemented in the internal host processor of a media session boarder controller 4, 5,
In an alternative embodiment, which is even preferred over the first alternative, controller functionality 24 con be implemented in a signaling session boarder controller controlling media session boarder controller 4,5, i.e. in Softswitch 6 of figure 1.
Figure 3 shows a flow chort of 0 method for assigning resources in the session boarder controller 20.
In step 31 □ call request for a voice coll arises. For example an end used in network 1 places a coll to an end user in network 3.
Step 32 determines whether the coll coming from network 1 to gateway 7 requires transcoding.

If so, step 33 determines the DSP capacity in of gatewoy 4 that will remain if gatewoy 4 serves the call. This remaining capacity is denoted with C.
Step 34 determines a threshold value T, which depends on the number of idle trunks gateway 4 is designed to serve.
Step 35 determines whether the remaining copacity C is greater than or equal to the threshold value T,
If not, the call is rejected in step 36. If so, step 37 assigns the required DSP resources ond routes the coll through gateway 4 'into network 3.
If the call requires no transcoding as determined in step 32, the call is also accepted and step 37 assigns the required DSP resources.
Optionally, a further check 38 con be introduced which determines whether idle credits are available. This step is optional, since depending on the rules used to determine the threshold value T, this situation con occur or not.

What is claimed is
1. A method of assigning transcoding resources in a session boarder
controller (4, 5; 20} interconnecting peering packet networks (1, 2, 3)
supporting packetized voice transport; the method comprising the steps of:
- determining for an incoming call whether transcoding is required; and if she- determining an amount of idle transcoding resources in said session boarder controller {4, 5; 20);
- determining a threshold value that depends on the number of idle trunks available at said session boarder controller (4, 5; 20); and
- assigning transcoding resources to said incoming call if the amount of idle
transcoding resources that will remain after resource assignment is greater
than said threshold value, and rejecting said call otherwise.
2. The method of claim 1, wherein soid amount of transcoding resources Is
measured in arbitrary units and wherein each codec supported by sold session
boarder controller has assigned a certain amount of said units corresponding
to the amount of transcoding resources it requires for processing.
3. The method of claim 1, wherein said threshold is chosen in such a way that it becomes smaller the more trunks ore busy.
4. The method of claim 1, wherein said threshold Is a linear function of the number of Idle trunks.

5. A session boarder controller (4, 5; 20} for use between peering networks [1,
2, 3) supporting packetized voice transport; said session border controller (4,
5; 20) comprising:
- J/O means (21, 22) having an I/O capacity that corresponds to at least a
predefined number of trunks;
- digital signal processing means {23a, 23b, 23c) adapted to convert between different type of voice codecs used for packetized voice transport of in incoming or outgoing connections, said digital signal processing means (23a, 23b, 23c) having limited processing capacity; and
- control means (24) adapted to determine Idle processing capacity of said digital signal processing means {23a, 23b, 23c), and if a connection to be established is a resource consuming connection that requires codec conversion to reject said connection, if the total amount of idle processing copacity that will remain offer resource assignment falls below a threshold that depends on the number of idle trunks.
6. The session boarder controller of claim 5, wherein said digital signal
processing means are adapted to support at least two of the list G7l 1, G729,
G723, G726, andAMR.
7. The session boarder controller of claim 5, wherein said I/O means (21, 22)
and said digital signal processing means (23a, 23b, 23c) are implemented in
a media session boarder controller (4, 5) and v/herein said control means (24)
are implemented in o separate signaling session boarder controller (6)
controlling said media session boarder controller (4, 5).

Documents:

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Patent Number

268602

Indian Patent Application Number

4467/CHENP/2009

PG Journal Number

37/2015

Publication Date

11-Sep-2015

Grant Date

07-Sep-2015

Date of Filing

29-Jul-2009

Name of Patentee

ALCATEL LUCENT

Applicant Address

3, AVENUE OCTAVE GREARD- 75007 PARIS.

Inventors:

#	Inventor's Name	Inventor's Address
1	RAINER BAEDER,	SCHONBLICKWEG 5, 70771 LEINFELDEN
2	HARTMUT SCHMIDT,	RUDOLF-YELIN-STRASSE 4, 71717 BEILSTEIN,

PCT International Classification Number

H04Q7/30

PCT International Application Number

PCT/EP2008/051047

PCT International Filing date

2008-01-29

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	07300788.2	2007-02-12	EUROPEAN UNION