CN1382362A

CN1382362A - Method and arrangement for connecting access network to switching device

Info

Publication number: CN1382362A
Application number: CN 00814617
Authority: CN
Inventors: G·梅格尔; B·达施; H·勒斯林舍菲; J·辛格
Original assignee: Siemens AG
Current assignee: Siemens AG
Priority date: 1999-10-22
Filing date: 2000-10-18
Publication date: 2002-11-27
Also published as: EP1222837A2; WO2001030111A3; BR0014923A; DE19951047B4; AR026199A1; WO2001030111A2; DE19951047A1

Abstract

The invention relates to a method and an arrangement for connecting terminals (UT) to a switching device (LE), comprising a connecting device (IAD) for connecting said terminals (UT) to an access network (AN) and an input adapter device (IAT) for linking the access network (AN) to V5-interfaces (V5IF) of the switching device (LE). The signalling information that has to be exchanged between the connecting device (IAD) and the switching device (LE) according to the VP5 protocols is at least partially conveyed between the connecting device (IAD) and the input adapter device (IAT) in a common signalling channel (CCSC).

Description

Be used for Access Network is connected to method and apparatus on the switching equipment

According to the reference model of being located at the V5 interface between switching equipment and its Access Network, Access Network is regarded as a kind of unit that can not further divide again, utilizes the PSTN (public switch telephone network) of simulation or ISDN (integrated services digital network) terminal of numeral-be also referred to as in technical literature UT (user terminal) or CTE (house exchange system)-and combine a plurality of users in this unit.At this, this V5 interface or be constructed to nonconcentrated V5.1 interface, or the V5.2 interface that is constructed to concentrate.Yet,, in the scope of America, normally utilize similar reference model and use Telecordia GR303 interface for substituting V5 interface popular in European scope.Described interface has been made regulation in following document:

The V5.1 interface:

-international ITU standard is G.964, " V-INTERFACES AT THE DIGITAL LOCALEXCHANGE (LE): V5.1 INTERFACE (BASED ON 2048kbit/s) FOR THESUPPORT OF ACCESS NETWORK (AN) [the V interface at digital local switch place: the V5.1 interface (based on 2048 bps) that is used to support Access Network] ", 06/94

-zonal etsi standard ETN 300 324-1: " V5.1 interface for thesupport of Access Network (AN) Part 1:V5.1 interfacespecification[is used to support the V5.1 interface section 1:V5.1 interface regulation of Access Network] ", 02/94-changes " amendment A1 ", 01/96 into

-international ITU standard is G.965, " V-INTERFACES AT THE DIGITAL LOCALEXCHANGE (LE): V5.2 INTERFACE (BASED ON 2048kbit/s) FOR THESUPPORT OF ACCESS NETWORK (AN) [the V interface at digital local switch place: the V5.2 interface (based on 2048 bps) that is used to support Access Network] ", 03/95

-zonal etsi standard ETN 300 347-1: " V5.2 interface for thesupport of Access Network (AN) Part 1:V5.2 interfacespecification[is used to support the V5.2 interface section 1:V5.2 interface regulation of Access Network] ", 09/94-changes " amendment A1 ", 05/97 into

The GR303 interface:

The general standard GR303-CORE that requires of-regional Telcordia, " IntegratedDigital Loop Carrier System Generic Requirements; Objectives; the general requirement of and Interface[Integrated Digital Loop Carrier system, task and interface] ", version 2,09/98

At this, for the summation through needed all state informations of described interface control transmission process, message and process is known as agreement.For through V5 interface control transmission process, need to adopt a plurality of agreements usually.At this, people are referred to as an agreement, a plurality of sub-protocol according to thinking methods, perhaps are referred to as to have the protocol groups of a plurality of agreements.

In the scope of contemporary standardization, according to so far model and the Access Network that is regarded as similar unit further is divided into connection device IAD (integrated access equipment) and interconnecting device IAT (integrated access terminal) again.In technical literature, connection device also is known as NT (network terminal) or CP-IWF (Subscriber Unit IWF), and described interconnecting device is known as CO-IWF (central office IWF).At this, described terminal always is connected on the connection device that is generally, and described switching equipment links to each other with in case of necessity a plurality of interconnecting devicies.This reference model is for example document " Baseline Text for Loop Emulation Service UsingAAL2[utilizes the baseline text of the loop artificial service of AAL2] ", atm forum, BTD-VTOA-LES-01.02.doc, 09/99, told about in the accompanying drawing 1.Disclose also in addition in the document in Access Network that connection device and interconnecting device are connected to ATM is online.The signaling flow that for example transmits D (control) channel in for the communication traffic streams of being transmitted in affiliated B (load) channel between terminal and the switching equipment with for the control transmission process, they are utilize-to be assigned to virtual connections VCC (connection of ATM virtual channel)-ATM cell usually and to transmit according to AAL2 (ATM Adaptation Layer type 2) agreement in ATM nets.This agreement is at international ITU standard I .363.2, " B-ISDN ATM Adaptation Layer Specification; Type 2 AAL[B-ISDN ATM Adaptation Layer standards: the 2nd type ALL] ", told about in 09/97.This whole proposal is called as " the loop artificial service of ATM carrying " in professional domain.Simultaneously following problem is known nowadays, promptly at unified Access Network and standardized V5 Application of Interface is divided in the modeled Access Network in ground to this quilt again.

Therefore, the present invention based on task be to using the V5 interface to construct non-unified Access Network.This task is solved by the feature of claim 1.

Main aspect of the present invention is that a kind of being used for is connected to method at least one switching equipment to terminal, this method has utilized at least one to be assembled to Access Network usually, be used for described terminal is connected to connection device on the Access Network, at least one is assembled to Access Network equally usually, be used for described Access Network is connected to interconnecting device on the described switching equipment, at least one V5 interface between described interconnecting device and switching equipment, and at least one between described connection device and interconnecting device-be empty-common signaling channel in case of necessity, wherein, in described common signaling channel, transmit those at least in part and need the signaling information that between described connection device and switching equipment, transmits at least because of adopting described V5 interface.Major advantages more of the present invention are as follows:

-it has disclosed following approach in principle, promptly how to use the Signalling method based on the V5 standard in a quilt divides the modeled Access Network in ground again,

-be used for coming the protocol instance of processing signaling information in switching equipment, to remain unchanged at least according to the defined agreement of V5 standard,

-for the common signaling channel of control between interconnecting device IAT and connection device IAD can use existing method fully in the same manner, because on described V5 interface, also set up common signaling channel,

-can reuse the regulation of described V5 standard fully,

-interconnecting device and connection device can be made economically best.This is very favorable to the preproduction phase for example, because have very important significance at this stage economic factor tool,

-can directly use the repertoire scope that in the V5 standard, defines for controlling in the connection between terminal and the switching equipment,

Even if-using quilt to divide again under the situation of the modeled Access Network in ground, also can provide and identical functions scope when using the Access Network of unified modelization reliably at terminal UT place.

According to a kind of expansion scheme of the inventive method, the signaling information that is used to control described V5 interface is exchange-claim 2 between described interconnecting device and switching equipment only.A kind of improvement project regulation of the present invention; according to applied first agreement on described V5 interface: protection agreement, bearer channel connection protocol or LCP and the signaling information set up only transmits between described interconnecting device and switching equipment, and according to applied second agreement on described V5 interface: isdn signaling agreement, pstn signaling agreement or control protocol and the signaling information set up be transmission-claim 3 between described connection device and switching equipment at least.Can minimize thus that transmission in the described interconnecting device expends, required transmission capacity and the disposal cost in described connection device in described common signaling channel.

According to a kind of improvement of the inventive method, described signaling information utilizes following protocol elements to transmit in described signaling channel, promptly this protocol elements on its structure corresponding to element-claim 4 of in described agreement, being set up.The transmission that can minimize thus in the described interconnecting device expends, and its reason is that protocol elements is identical, so only need be at interconnecting device and this protocol elements of substantially transparent ground transmission.Thereby need not duplicate described signaling information between the protocol elements of different structureization, this is very favorable.

A kind of flexible program regulation of the inventive method adopts an Additional Agreement between described connection device and interconnecting device, utilize this agreement to control the activation and the deactivation-claim 5 of described connection between connection device and interconnecting device at least.Realized thus to coordinating the needed function of distributed treatment of described agreement.Thereby also advantageously supported the function that provides all to stipulate by described agreement.

According to a kind of improvement project of the inventive method, the public control protocol part of described control protocol has been replenished continuity check function-claim 6 at least.This makes only checks the interference of common signaling channel to become possibility on logical layer.To this, the described finite state machine of setting up by the V5 agreement is changed to definite malfunction under failure condition, has advantageously avoided the nondeterministic statement in the cooperation of the finite state machine that is distributed thus.

According to a kind of expansion scheme of the inventive method, at least under the situation of utilizing ATM cell to transmit between described connection device and the interconnecting device, it is virtual channel-claim 7 of 8 that described common signaling channel is configured to channel number.By use the channel number reserve as signaling channel in ATM is 8 channel, can use existing software to control this channel unchangeably, and can repeatedly use it more under situations about using.Thereby to for the needed instrument of Control Software be very effective.

A kind of flexible program according to the inventive method, at least under the situation of utilizing ATM cell to transmit between described connection device and the interconnecting device, the described signaling information of setting up according to the isdn signaling agreement transmits in the virtual channel of additional, terminal-specific-claim 8.Cancelled thus and in connection device, handled described signaling information.This complexity that is lowered is very favorable for described connection device especially, because this connection device shows as the product of batch process, its cheap manufacturing is very significant.

Other advantageous modification of the inventive method is provided by dependent claims, and the preferred embodiment that is used to carry out the inventive method is provided by additional claim.

Tell about method of the present invention in detail by a plurality of accompanying drawings below.Wherein:

Fig. 1 shows a kind of network configuration with block diagram, and it has the unified Access Network according to the V5 reference model,

Fig. 2 shows a kind of network configuration with Access Network of further being divided with block diagram,

Fig. 3 shows network configuration shown in Figure 2 with block diagram, and it has additional ATM net between connection device IAD and interconnecting device IAT,

Fig. 4 shows network configuration shown in Figure 3 with block diagram, and it has additional xDSL device between connection device IAD and ATM net, and

Fig. 5 shows the network configuration shown in Fig. 3 or 4 with block diagram, and it has virtual connections VC of the present invention.

In Fig. 1, drawn to example according to the network configuration of V5 reference model.Wherein, at the terminal interface UTIF place of the end side of unifying Access Network AN, have at least a terminal UT to be connected on the connection device NT (be also referred to as CP-IWF, but be called as IAD mostly hereinafter) that indicates with dotted line.Described Access Network AN is connected at least one switching equipment LE at the V5 of exchange side interface V5IF place.Using the agreement V5P that on described V5 interface V5IF, uses between these two unit.

Figure 2 illustrates a kind of network configuration according to the contemporary standard method.This network configuration is consistent with Fig. 1 basically.But Access Network AN is divided into the connection device IAD (also being known as CP-IWF) of end side and the interconnecting device IAT (also being known as CO-IWF) of exchange side once more, and wherein in described connection device IAD, its alternative title is represented with NT by dotted line.Between described connection device IAD and interconnecting device IAT, set up at least one signaling channel CCSC of the present invention.Also setting up the agreement V5P that on described V5 interface V5IF, moves between Access Network AN and the switching equipment LE in addition.But according to the present invention, in the described agreement of setting up according to the V5 standard some just use-represent with the first agreement V5P ' between interconnecting device IAT and switching equipment LE in the drawings, and in the agreement that should set up according to the V5 standard other use between connection device IAD and switching equipment LE at least-and in the drawings with the second agreement V5P " represent.At this, last-mentioned agreement is to transmit in the common signaling channel CCSC between connection device IAD and interconnecting device IAT.In addition, V5 is functional completely as long as for example need provide at terminal UT place, then can also set up additional agreement A2CC (control of AAL2 channel)-this selection possibility to represent with dotted line in the drawings between connection device IAD and interconnecting device IAT.Agreement V5P " be also referred to as protocol groups or be called agreement A2LC (control of AAL2 loop) for short with the summation of Additional Agreement A2CC.

Figure 3 illustrates network configuration another kind of and Fig. 2 basically identical.Its supplementary provisions are that connection device IAD and interconnecting device IAT are connected with each other by ATM net ATMN, and are connected on the atm interface ATMIF of this ATM net.Set up Additional Agreement A2LC (control of AAL2 loop) forcibly for network configuration in addition.It can also be seen that simultaneously; the described first agreement V5P ' for example may be embodied as protection agreement PP, bearer channel connection protocol BCC or LCP LP, and the described second agreement V5P " such as may be embodied as isdn signaling agreement DSS, pstn signaling agreement PSP or control protocol CP.At this, described control protocol CP comprises at least one public control protocol portion C C.

Figure 4 illustrates network configuration another kind of and Fig. 3 basically identical.Its supplementary provisions are that connection device IAD is not directly but is connected on the ATM net ATMN by couple in multiplexer DSLAM (Digital Subscriber Line Access Multiplexer) indirectly.At this, on the physical interface between connection device IAD and the couple in multiplexer DSLAM, used a kind of transmission method that is called as xDSL in professional domain.But this is on the higher protocol layer and transmits also in addition that ATM cell-this is that expansion title DSLAM (ATM) with described couple in multiplexer DSLAM represents.Therefore, from the viewpoint that is taken out by physical interface of ATM protocol layer, described connection device IAD and interconnecting device IAT also are connected with each other.This situation has at length been described at Fig. 5.

Figure 5 illustrates network configuration a kind of and Fig. 3 or 4 basically identicals.But, described ATM net ATMN or couple in multiplexer DSLAM are not shown for the viewpoint that the quilt that described ATM protocol layer is described takes out.The virtual connections VCC (ATM) that shows to substituting described ATM protocol layer be included in this virtual channel VC in being connected.Set up independent common signaling channel CCSC between connection device IAD and interconnecting device IAT, it preferably has channel number CID=8.The bearer channel B and the control channel D that interrelate with terminal always transmit in independent virtual channel, that is to say, according to the configuration of this example, the signaling information of setting up by isdn signaling agreement DSS in control channel D is not in common signaling channel CCSC but transmits in the virtual channel VC of terminal-specific.This transmission course is preferably controlled according to the AAL2 agreement.Also can select to adopt the AAL5 agreement.

For this embodiment, that the network configuration of supposing Fig. 3 has is shown in Figure 5, be located at the virtual connections VCC structure between connection device IAD and the interconnecting device IAT in ATM net ATMN.To this, in interconnecting device IAT such as aspect content, handle agreements such as protection agreement PP, bearer channel connection protocol BCC and LCP LP, and in connection device IAD, handle agreements such as described pstn signaling agreement PSP and control protocol CP.Described isdn signaling agreement DSS is handling in terminal UT aspect the content basically, and just transmission pellucidly in connection device IAD.But, in connection device IAD, also can aspect content, handle described isdn signaling agreement DSS in case of necessity as long as need.

Above-mentioned in principle all agreements can be transmitted in common signaling channel CCS, and wherein this common signaling channel is to be that the virtual channel VC of CID=8 gives described ATM net ATMN structure as channel number.Scheme is transmitted described isdn signaling agreement DSS at least in the distinctive channel VC of terminal as an alternative, has cancelled in connection device IAD thus otherwise the addressing scheme coupling of needed common signaling channel CCSC.This is very favorable, because otherwise, must be except in interconnecting device IAT and carry out the matching addresses with the addressing scheme of the described public V5 signaling channel of on V5 interface V5IF, being set up at V5 interface V5IF, also in Access Network AN, carry out matching addresses for the second time.

Preferably, the structure that the protocol elements of using in described common signaling channel CCSC the has V5 standard with affiliated basically is defined identical, thus, in interconnecting device IAT at the second agreement V5P " complexity of carrying out signaling process is reduced to substantially and transmits relevant protocol elements.Described agreement V5P " in ATM net ATMN, preferably utilize the ATM cell of abideing by ATM agreement AAL2 to transmit.

Described Additional Agreement A2CC for example also is added on the existing mechanism of employed ATM agreement AAL2.At this, the data link layer of described Additional Agreement A2LC is for example corresponding to the data link sub-layers LAPV5 that abides by etsi standard ETN 300 347 the 10th chapters and ETN 300 324.Under the situation of using ATM the 2nd adaptation layer AAL2, use transmission error to detect sublayer SSTED by described Additional Agreement A2LC.This sublayer is used Segmentation and Reassembly sublayer SSSAR again.Described sublayer SSTED and SSSAR are assigned to so-called service specific convergence sublayer SSCS, the latter is once at international ITU standard I .366.1, " Segmentation and ReassemblyService Specific Convergence Sublayer for the AAL type 2 (the Segmentation and Reassembly service specific convergence sublayers that are used for AAL type 2) " were told about in 06/99.Briefly say, between connection device IAD and interconnecting device IAT, draw following agreement cooperation:

When in common signaling channel CCSC, transmitting, presentation protocol V5P " and the agreement A2LC (control of AAL2 loop) of the summation of Additional Agreement A2CC need carry out addressing to each agreement because of a plurality of agreements so that distinguish them and it correctly be transferred to the protocol instance that is used to handle described agreement V5P or Additional Agreement A2CC.The envelope function address (EFA) that described for this reason protocol elements utilization is located in the V5 standard identifies.Set up following envelope function address:

Agreement	????EFA
Agreement	????EFA	Isdn signaling agreement DSS	????＜＝8175
Pstn signaling agreement PSP	????8176	Isdn signaling agreement DSS	????＜＝8175
Pstn signaling agreement PSP	????8176	Control protocol CP	????8177
Bearer channel connection protocol BCC	????8178	Control protocol CP	????8177
Bearer channel connection protocol BCC	????8178	Protection agreement PP	????8179
LCP LP	????8180	Protection agreement PP	????8179
LCP LP	????8180	Additional Agreement A2CC	????8181

Described control protocol CP for example comprises two sub-protocols: public control sub-protocol CC 1) user port control sub-protocol and 2), both all told about at etsi standard ETN 300 347 the 15th chapters or etsi standard ETN 300 324 the 14th chapters for they.Sub-protocol CC preferably only uses following function at agreement A2LC:

-variant and interface ID

-restart (PSTN)

-block/do not block all relevant PSTN/ISTN user ports, respectively as asking, accept, refuse and finishing.

According to the structure of A2LC agreement, described public control sub-protocol CC is replenished the continuity checking function by for example adding two following protocol elements:

-A2LC continuity check

-A2LC continuity check ACK

As long as for example periodically exchange this protocol elements, then can find the interference of described common signaling channel CCSC.Under failure condition, for example represent that according to the V5 standard finite state machine of terminal UT state is just carried out the transition to blocked state.

Described Additional Agreement A2CC packs into because of ATM net ATMN, and is used to activate and deactivate the described virtual channel VC-that uses according to the AAL2 agreement at least and abbreviates " AAL2 channel " hereinafter as.It for example comprises following protocol elements:

-activate

-activate and finish

-activate and refuse

-deactivation

-deactivation is finished

-deactivation refusal

-examination-option

-examination is finished-option

-IAD fault-option

-IAD fault recognition-option

Activating and deactivate the AAL2 channel controls by sending corresponding protocol element " activation " or " deactivation " at exchange side.Utilizing the corresponding protocol element that this is made in end side replys.This process for example can realize on described V5 interface V5IF during the channel of setting up for transmission B channel is occupied.Preferably, described protocol elements " examination " and " examination is finished " are optionally, and are provided for checking following distribution: the channel number CID of AAL2 channel  AAL2 channel.Equally, described protocol elements " IAD fault " and " IAD fault recognition " also are optionally, and are used to where necessary the malfunction in the described connection device IAD is notified to described interconnecting device IAT.

When being applied to network configuration shown in Figure 4, the present invention can produce extraordinary advantage.In this configuration, provide higher transmission capacity by the xDSL technology on the existing copper cash.So-called multi-line telephone business can be provided thus, wherein can provide more channel than the channel 2B+D that in ISDN, is generally three usually.At this, because the flexibility of the statistics volume controlled of described common signaling channel CCSC, and the flexible number of netting the virtual channel VC of ATMN in conjunction with ATM, thereby can further adapt to the more great fluctuation process of needed transmission channel quantity of each terminal UT and capacity best than reliable PSTN and ISDN Access Network AN, to be used to transmit useful information and signaling information.At this, transmission of Information also is that the form with ATM cell realizes on the xDSL transmission link, wherein preferably is assigned to the information of a plurality of terminal UT among the virtual connections VCC that is adopted herein according to the AAL2 protocol transmission.

If use other network, for example, then also can make to use the same method by similar mode based on the IP network of IP (Internet Protocol) towards bag.For substituting the AAL2 agreement, be to use the distinctive agreement of IP herein, wherein these two kinds of agreements might not be repelled mutually.Therefore in the IP scope of ATM carrying, definitely can use IP and ATM agreement in combination.

This further equivalent is that professional term by similar call reflects in professional domain, for example be referred to as " the loop artificial service of ATM carrying " or " the loop artificial service of IP carrying " according to network configuration, perhaps, in based on scheme, be referred to as the voice of main useful information " voice of ATM carrying " (VoATM), " voice of IP carrying " (VoIP) or " voice of DSL carrying " (VoDSL).Therefore, for every kind of technology described herein and corresponding techniques thereof, the present invention can be used by the relevant technologies personnel in the mode of equivalence easily.

Claims

1. be used for terminal (UT) is connected to method at least one switching equipment (LE), it has utilized

-at least one connection device (IAD) is used for described terminal (UT) is connected to Access Network (AN),

-at least one interconnecting device (IAT) is used for described Access Network (AN) is connected at least one V5 interface (V5IF) of described switching equipment (LE),

-at least one is positioned at the common signaling channel (CCSC) between described connection device (IAD) and the interconnecting device (IAT),

Wherein,

In described common signaling channel (CCSC), transmit those at least in part and need the signaling information of transmission between described connection device (IAD) and switching equipment (LE) at least because of adopting described V5 interface (V5IF).

2. the method for claim 1 is characterized in that:

Be used to control the only exchange between described interconnecting device (IAT) and switching equipment (LE) of signaling information of described V5 interface (V5IF).

3. method as claimed in claim 1 or 2 is characterized in that:

According to go up applied first agreement (V5P ') at described V5 interface (V5IF):

-protection agreement (IP),

-bearer channel connection protocol (BCC), or

-LCP (LP)

And only transmission between described interconnecting device (IAT) and switching equipment (LE) of the signaling information of setting up, and according to applied second agreement on described V5 interface (V5IF) (V5P "):

-isdn signaling agreement (DSS),

-pstn signaling agreement (PSP), or

-control protocol (CP)

And the signaling information of setting up transmission between described connection device (IAD) and switching equipment (LE) at least.

4. as the described method of one of claim 1～3, it is characterized in that:

Described signaling information utilizes following protocol elements to transmit in described signaling channel, promptly this protocol elements on its structure corresponding to the element of in described agreement (V5P ', V5P "), being set up.

5. as one of above-mentioned claim described method, it is characterized in that:

Between described connection device (IAD) and interconnecting device (IAT), adopt an Additional Agreement (A2CC), utilize this agreement to control described activation and the deactivation that is positioned at the connection between connection device (IAD) and the interconnecting device (IAT) at least.

6. as one of above-mentioned claim described method, it is characterized in that:

The public control protocol part (CC) of described control protocol (CP) has been replenished the continuity check function at least.

7. as one of above-mentioned claim described method, it is characterized in that:

At least under the situation of utilizing ATM cell to transmit between described connection device (IAD) and the interconnecting device (IAT), described common signaling channel (CCSC) is constructed to the virtual channel of channel number (CID)=8.

8. as one of above-mentioned claim described method, it is characterized in that:

At least under the situation of utilizing ATM cell to transmit between described connection device (IAD) and the interconnecting device (IAT), the described signaling information of setting up according to isdn signaling agreement (DSS) transmits in the virtual channel (VC) of additional, terminal-specific.

9. be used to carry out device as the described method of one of claim 1～8.

10. be used for terminal (UT) is connected to device at least one switching equipment (LE), have

-at least one connection device that is assembled (IAD) is used for described terminal (UT) is connected to Access Network (AN),

-at least one is positioned at the common signaling channel (CCSC) between described connection device (IAD) and the interconnecting device (IAT), is used for transmitting at least those and needs the signaling information of transmission between described connection device (IAD) and switching equipment (LE) at least in part because of adopting described V5 interface (V5IF).