GB2413724A - Path replacement in voip - Google Patents
Path replacement in voip Download PDFInfo
- Publication number
- GB2413724A GB2413724A GB0407553A GB0407553A GB2413724A GB 2413724 A GB2413724 A GB 2413724A GB 0407553 A GB0407553 A GB 0407553A GB 0407553 A GB0407553 A GB 0407553A GB 2413724 A GB2413724 A GB 2413724A
- Authority
- GB
- United Kingdom
- Prior art keywords
- endpoint
- connection
- pbx
- endpoints
- payload
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M3/00—Automatic or semi-automatic exchanges
- H04M3/42—Systems providing special services or facilities to subscribers
- H04M3/58—Arrangements for transferring received calls from one subscriber to another; Arrangements affording interim conversations between either the calling or the called party and a third party
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L65/00—Network arrangements, protocols or services for supporting real-time applications in data packet communication
- H04L65/80—Responding to QoS
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M2203/00—Aspects of automatic or semi-automatic exchanges
- H04M2203/20—Aspects of automatic or semi-automatic exchanges related to features of supplementary services
- H04M2203/2022—Path replacement
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M2207/00—Type of exchange or network, i.e. telephonic medium, in which the telephonic communication takes place
- H04M2207/20—Type of exchange or network, i.e. telephonic medium, in which the telephonic communication takes place hybrid systems
- H04M2207/203—Type of exchange or network, i.e. telephonic medium, in which the telephonic communication takes place hybrid systems composed of PSTN and data network, e.g. the Internet
Landscapes
- Engineering & Computer Science (AREA)
- Signal Processing (AREA)
- Multimedia (AREA)
- Computer Networks & Wireless Communication (AREA)
- Data Exchanges In Wide-Area Networks (AREA)
Abstract
In a hybrid voice network a method of enhancing call transfer between three endpoints, comprising establishing a call connection between a first endpoint (A) and a second endpoint (B), establishing a call connection between said first endpoint and a third endpoint (C), communicating between said second and third endpoints, from the third endpoint, testing whether it is possible to establish a direct connection with said second endpoint, establishing said direct connection and terminating said connection between said first endpoint and either or both of said second and third endpoints.
Description
24 1 3724
PATH REPLACEMENT METHOD FOR VOIP SYSTEM
This invention relates to hybrid voice networks for example those consisting of TDM (carrying voice data) and Internet Protocol or other such systems, i.e. TDM Telephone systems where voice data is passed over the lnternet, LANS etc. and includes IP phone calls to public 1SDN. These are referred to hereinafter as hybrid VolP systems.
In a VoIP (hybrid) systems, inter-working protocols are used. One such is the Q- Interface signalling protocol (QSIG), a signalling standard for logical signalling between two private branch exchanges (PBX), and enables enterprises to run features across a heterogeneous telephony network comprising PBX's or PINX's (Private integrated Network Exchange) from different vendors. CorNet-NQ is the Siemens implementation of QSIG. These inter-working protocols are used to optimise the payload path in case of supplementary services such as call transfer. Optimisation focuses mainly on the payload (i.e. routing the voice transmitted via the wire path), rather than the signalling path of the connection. In pure VoIP networks often use end to end payload control such as H.323 (A VoIP standard by ITU-T which defines a set of protocols for voice over IP). One of these is "third party pause", which controls the payload by a third party on the network.
The third party pause and re-route is more a method or procedure provided by H.323 rather than a protocol itself. The problem with such hybrid networks is that any conversion from TDM to IP or vice versa comes along with increased latency, jitter etc. Another problem is the cost in terms of TDM gateway channels (for signals and data) which cannot be released because of ineffective payload paths.
Such problems are inevitable and difficult to minimise where there are two VolP systems connected over an ISDN line, e.g., the problem with the prior art is that such hybrids networks require conversion from TDM to IP and vice versa. In a network consisting of three VoIP systems a call may come in from public ISDN via a VoIP system acting as TDM gateway (is' conversion) and reaches the second VoIP system, where an analogue phone is connected (2n conversion). These two conversions cannot be avoided, but if the analogue phone now consults to an IP phone at a third VoIP system and afterwards transfers the call from the ls' to the 3rd VolP system you have perforce a third conversion in the second VoIP system.
The invention overcomes this problem and involves optimising the payload path which means that the call from public ISDN is converted to IP only at the first VoIP system and travels directly to the third VoIP system without any other conversions.
The invention comprises, in a hybrid voice network a method of enhancing call transfer between three endpoints, comprising establishing a call connection between a first endpoint (A) and a second endpoint (B); establishing a call connection between said first endpoint and a third endpoint; communicating between said second and third endpoints; from the third endpoint, testing whether it is possible to establish a direct connection with said second endpoint; establishing said direct connection and terminating said connection between said first endpoint and either or both of said second and third endpoints.
The endpoints may be connected via the Internet or a LAN.
This is achieved by using the combination of classic TDM path replacement procedures together with the capability of VoIP end points to establish an end to end payload connection in order to optimise the resources in a hybrid system. These are resources which are needed are for example DSP channels on the gateway linecard, channels in the TDM switching matrix. Path replacement is the mechanism to optimise a connection in the TDM network, e.g., after a transfer. Imagine there is a phone A at a PBX A calling a phone B at PBX B. A consults to C in PBX C and transfers the call (B and C are now connected). Without path replacement the connection from phone B goes via PBX B. PBX A, PBX C to phone C. With path replacement the three PBX's try to optimize the connection, respectively from phone B via PBX B and PBX C to phone C (without involving PBX A) The statement "not involving PBX A" is correct after successful path replacement, during the path replacement the PBX A is involved in the procedure.In the following, the term "primary end" within a three party scenario is the "held" connection, e.g. A to B in the above example, and the term "secondary end" is the active (consultation) connection, e.g. A to C. The invention will now be described with reference to the following figures of which: Figures 1, 2 and 3 illustrate the operation an example of the invention.
Figure 5 shows the connections before and after call transfer.
Figures 6 and 7 illustrate the floe of data and control signals.
In a pure TDM Network the path replacement procedures are terminated between the primary and secondary PBX. Because in TDM based PBX systems the intelligence is located in the PBX itself, the PBX acts on behalf of the endpoint or subscriber. Because the QSIG protocol defines a networking protocol (remember that this describes how to PBX's are able to interwork), the PBX respectively the PINX are seen as terminating instances. Whatever the PBX / PINX takes to the connected phones or endpoints is not visible to the other PBX/PINX and therefore not scope of QSIG]. The optimisation of the allocated sources (lo-channels, the channel in the ISDN/TDM network where the voice is transported) has to be done between the primary and secondary PBX. The mechanism is enhanced in the way that VoIP points are included in order to allow an end to end payload establishment on receipt of a path replacement proposal. In contrast to the TDM world, the endpoint VolP itself has to re-route the payload, which has to be handled by the protocol. In other words, the PBX is not the terminating instance. After successful call transfer, the primary end invokes a path replacement procedure. This invocation causes the secondary end to setup a new connection using a payload proposal of endpoint C (i.e. OLC data including RTP/RTCP ports) (OLC - Open logical channel. A signalling command in the H.323 standard to open up a payload connection.) In order to provide the payload proposal to the primary end, the secondary PINX has to query this information from the endpoint C. On the primary end the payload proposal of endpoint C is given to endpoint B. whereas endpoint C is able to choose a payload setting and replies with its own payload settings. In the last step the PINX B connects to PINX C and the payload data is transferred towards the secondary end completing the backward establishment of the new signalling connection towards the primary end. Endpoint B and endpoint C are now able to exchange payload data. The term "backward establishment of the new signalling connection" is explained as follows: If phone A calls phone B and consults to C, both B and C have an incoming call. If A transfers B to C in the next step, C receives a new partner on the existing connection. To perform a path replacement (to optimise the connection), the C side now tries to establish a new connection to B. Form C's standpoint it is outgoing or "backward". On receipt of the path replacement invocation, the secondary PINX establishes a new signalling connection towards the primary end (using H.225 SETUP in the example of the figures) including the data of the new media session and the CorNet-NQ SETUP message. The primary PINX passes on the proposal for the new media session towards the end point B and if the end point B accepts the proposal, replies with a connect message towards the secondary end with a H.225 CONNECT in the example). A signalling message (H.323 FACILITY in the example) connects to endpoint C including endpoint B. Additionally existing media session towards PINX A respectively endpoint A is closed. On the secondary end the media data of endpoint B is passed on towards endpoint C. At this time a new signalling path between primary and secondary PINX and a new direct media session is set up for either voice, video or data between endpoints B and C is established. In the next step the old signalling path via PINX A is and the existing media session towards PINX A respectively endpoint A released.
In one example the endpoints are involved into the path replacement procedure, because they are needed in order to provide their payload data. This is different to the TDM world, where the PBX / PINX are able to perform the path replacement by their own (without any communication to query the payload data towards the endpoints) In the drawings, the following terms are used: Gateway: in an IP world an entity providing access to the TDM world (conversion of signalling and payload), an IP/TDM Gateway.
Gatekeeper: in the H.323 a central entity of control to route call signalling, address resolution, authorization, policy handling etc. Call Processing: piece of SW sitting in a classic TDM PBX, handling the call establishment, policy management etc. Linecard: a piece of Hardware providing access to the switching matrix of a TDM PBX, e.g. an analogue linecard IP Cloud: a LAN/ Intranet/ Internet HP3/SK: a VolP platformlRZ: A Siemens VoIP platform] h232CalllD1, CalllD2, CalllD3: are Call Identifier of a H.323 Call MOH: Music on Hold MediastreamB-A enabled: endpoint A and B have an established payload stream, e.g. A is able to speak to B and vice versa Transfer IND: indication of a transfer request fastStart: a H.323 data element providing payload paramenters between two endpoints in order to establish the payload stream (e.g. frame, UDP port number, etc.) Acceptance OLC: the partner accepts the received OLC command ProposalfastStart: one side proposes a payloadstream specifying the payload data NullOLC: an empty OLC command Tunnelled: tunnelling one protocol in another NQ-Facility: A CorNet-NQ facility message ctComplete. inv: a calltransferComplete.invocation message of the QSIG protocol NQConnect pRsetup.res a Cornet-NQ Connect message including a pathReplacement Result NQ disconnect a CorNet-NQ Disconnect message, a partner indicates that he wants to disconnect a connection NQ-RELEASE: a CorNet-NQ Release message, a receiver of a disconnect message replies with a release e.g. when he accepts the partners disconnect.
NQ REL COM: a CorNet-NQ Release complete message, the sender of a disconnect replies with release complete when receiving a release.
Claims (3)
1. In a hybrid voice network a method of enhancing call transfer between three endpoints, comprising i) establishing a call connection between a first endpoint (A) and a second endpoint (B) ii) establishing a call connection between said first endpoint and a third endpoint iii) communicating between said second and third endpoints iii) from the third endpoint, testing whether it is possible to establish a direct connection with said second endpoint, iv) establishing said direct connection v) terminating said connection between said first endpoint and either or both of said second and third endpoints.
2. A method as claimed in claim 1 where the endpoints are connected via the Internet or a LAN.
3. A method as claimed in claim 1 or 2 where at least two end points are in different private branch exchanges.
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB0407553A GB2413724A (en) | 2004-04-02 | 2004-04-02 | Path replacement in voip |
PCT/EP2005/002980 WO2005099241A1 (en) | 2004-04-02 | 2005-03-17 | Path replacement method for voip system |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB0407553A GB2413724A (en) | 2004-04-02 | 2004-04-02 | Path replacement in voip |
Publications (2)
Publication Number | Publication Date |
---|---|
GB0407553D0 GB0407553D0 (en) | 2004-05-05 |
GB2413724A true GB2413724A (en) | 2005-11-02 |
Family
ID=32247781
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB0407553A Withdrawn GB2413724A (en) | 2004-04-02 | 2004-04-02 | Path replacement in voip |
Country Status (2)
Country | Link |
---|---|
GB (1) | GB2413724A (en) |
WO (1) | WO2005099241A1 (en) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US8705566B2 (en) | 2010-01-28 | 2014-04-22 | Siemens Enterprise Communications Gmbh & Co. Kg | Method and apparatus in which call signaling messages bypass in-transparent switching nodes or networks |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2325374A (en) * | 1997-04-18 | 1998-11-18 | Rolm Systems | ISDN path replacement |
JP2000244581A (en) * | 1999-02-19 | 2000-09-08 | Fujitsu Ltd | Internet telephony void system |
US20030185375A1 (en) * | 1999-08-16 | 2003-10-02 | Albal Nandakishore A. | Call transfer system and method |
Family Cites Families (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1999005590A2 (en) * | 1997-07-25 | 1999-02-04 | Starvox, Inc. | Apparatus and method for integrated voice gateway |
BR0010556A (en) * | 1999-05-17 | 2002-02-19 | Siemens Ag | Process for converting a three-point telecommunication link, intermediated by the public communication network, into a two-point telecommunication link |
FR2843666B1 (en) * | 2002-08-14 | 2005-03-18 | Cit Alcatel | METHOD FOR OPTIMIZING ESTABLISHED COMMUNICATIONS IN A PRIVATE TELECOMMUNICATION NETWORK COMPRISING TWO SUB-NETWORKS USING RESPECTIVELY THE QSIG AND SIP PROTOCOLS |
-
2004
- 2004-04-02 GB GB0407553A patent/GB2413724A/en not_active Withdrawn
-
2005
- 2005-03-17 WO PCT/EP2005/002980 patent/WO2005099241A1/en active Application Filing
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2325374A (en) * | 1997-04-18 | 1998-11-18 | Rolm Systems | ISDN path replacement |
JP2000244581A (en) * | 1999-02-19 | 2000-09-08 | Fujitsu Ltd | Internet telephony void system |
US6724749B1 (en) * | 1999-02-19 | 2004-04-20 | Fujitsu Limited | Internet telephony system |
US20030185375A1 (en) * | 1999-08-16 | 2003-10-02 | Albal Nandakishore A. | Call transfer system and method |
Also Published As
Publication number | Publication date |
---|---|
WO2005099241A1 (en) | 2005-10-20 |
GB0407553D0 (en) | 2004-05-05 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US6754180B1 (en) | System, method, and computer program product for support of bearer path services in a distributed control network | |
US7092493B2 (en) | Methods and systems for providing lawful intercept of a media stream in a media gateway | |
US7986684B2 (en) | Multi-mode endpoint in a communication network system and methods thereof | |
US6879680B2 (en) | Method of and system for extending internet telephony over virtual private network direct access lines | |
US6404746B1 (en) | System and method for packet network media redirection | |
US7920690B2 (en) | Interworking of multimedia and telephony equipment | |
US8098672B2 (en) | Internet telephone system ensuring communication quality and path setting method | |
US20070019614A1 (en) | Method for providing a user interaction dialogue (uid) prior to connection acceptance by the called user | |
US20060187904A1 (en) | VoIP gateway apparatus | |
US7460520B2 (en) | Apparatus and method for using multiple call controllers of voice-band calls | |
US20040008837A1 (en) | Combining multimedia services with traditional telephony services in a public branch exchange | |
US6804254B1 (en) | System and method for maintaining a communication link | |
US20070041357A1 (en) | Interworking of hybrid protocol multimedia networks | |
US7006494B1 (en) | System and method for a virtual telephony intermediary | |
EP1198945B1 (en) | An ip based telephone system | |
US7408922B2 (en) | Communication between switched-circuit communication network and VoIP network domains | |
KR100279641B1 (en) | Signal exchange apparatus and method | |
US7701927B2 (en) | Method for transmitting communication data in a communication system | |
GB2465124A (en) | Access gateway and its operation method | |
Cisco | H.323 Applications | |
WO2005099241A1 (en) | Path replacement method for voip system | |
CN100499720C (en) | Realization method for providing multi-rate data information loading service | |
KR100952856B1 (en) | Hybrid ip pbx | |
KR100664841B1 (en) | Method for providing multiparty calling service in broadband convergence network and method thereof | |
Gou et al. | Multi-agent based softswitch |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |