BugFix

1

EWSDEWSD Based IN Services in Transit Network Nodes(TXS Services)

Definition

With EWSD Based IN Services in Transit NetworkNodes (TXS Services), alternative providers have theopportunity of also offering their services to subscribersin other networks.

This service operates on the calling side of the connec-tion. It is valid for analog and ISDN subscribers.

Services and types of connectionThe calling subscriber is connected to the network ofthe alternative provider either directly (e.g. via assignedlines) or remotely (e.g. via gateway lines). Subscribersare identified via their individual access lines (adminis-trated in the network node of the alternative provider)and/or via an authorization code.

Alternative provider customers are treated as analogsubscribers regardless of their access lines in theirhome network node (analog, ISDN, PBX analog/ISDN).Thus EWSD Based IN Services in Transit NetworkNodes are only available as voice connections.

Dial-upAccess

orTravel-Service

EWSD-transit

networknode

Alternativeprovider’snetwork

Calledsubscriber

Callingsubscriber

PBX

Lo-calnet-worknode

Lo-calnet-worknode

Benefits

... for the operator– cost-effective entry-level solution for

decentralized markets with a num-ber of smaller network operators

– alternative for service providers whoonly need a small number of fea-tures

– attractive and low-cost solutions forsubscribers

... for the subscriber– opportunity to use features that are

offered by alternative providers

2

In accordance with the defined dialing procedure, dif-ferent services are defined for the user of an alternativenetwork:• Dial-up Access• Travel Service

The various services result from the authorization of auser and the type of access to the network of an alter-native provider.

Dial-up Access

With Dial-up Access an alternative network providercan offer subscribers of another network provider ac-cess to their network via a dial-up number (with dialedor automatically prefixed carrier access code). In the in-coming gateway a check is made, using the directorynumber of the calling subscriber (CLI), to determinewhether the subscriber may use the carrier networkand its features.

A distinction is made between the types of connectiondescribed below:• Casual User Call without Identification

A subscriber who is connected to the network of an-other subscriber can also set up a connection viathe network of the alternative provider without priornotification.With this type of connection there are no entriesstored for the calling subscriber in the database ofthe alternative provider. As a result, connectionsare set up without identification. The calling sub-scriber cannot use any additional features of the al-ternative provider here.

• Registered Site Access Call

The following types of connection can be used bysubscribers for whom an access authorization isentered in the database of an alternative provider.– Registered Site Access, RSA, Call with Identifi-

cation via A-numberCalling subscribers can set up a connection viathe network node of an alternative provider evenif they are outside the network node of this pro-vider. In this case subscribers are identified inthe network node of the alternative provider bytheir directory number. Depending on the autho-rizations entered in the database, the subscribercan also use the features offered within this net-work.

– Registered Site Access, RSA, Call with Identifi-cation via A-number and Authorization Code.Calling subscribers can set up a connection viathe network node of an alternative provider evenif they are outside the network node of this pro-vider.Calling subscribers are identified in the networkof the alternative provider by their directory num-ber. In addition, subscribers are requested via asecond dial tone to enter an authorization codefor their identification using dual tone multi-fre-quency signaling (DTMF). Depending on the au-thorizations entered in the database, thesubscriber can also use the features offeredwithin this network.

Dial-upAccess

EWSDtransit

networknode

Alternativeprovider’snetwork

Calledsubscriber

Callingsubscriber

Lo-calnet-worknode

Lo-calnet-worknode

3

• Direct Access Line, DAL, Call

Private branch exchange subscribers who are con-nected directly to the network node of an alternativeprovider can set up a connection via the network ofthe alternative provider with or without identifica-tion:– Direct Access Line, DAL, Call without Identifica-

tionSubscribers of a PBX or PBX network who areconnected directly to a transit node can set upcalls via the network of an alternative providerwithout identification. The PBX dials the directaccess to the network node of the alternativeprovider.The main PBX number involved (pilot directorynumber) is not stored in the network node. As aresult calls are set up without identification. Call-ing subscribers cannot use any features withinthe alternative network here. Standard PBX fea-tures are available however.

– Direct Access Line, DAL, Call with Identificationvia A-number (and with/without AuthorizationCode)In contrast to the type of call described above,PBX or PBX network subscribers who are con-nected directly to a transit node can also set upcalls via the network of an alternative providerusing an identification code.The main PBX number involved (pilot directorynumber) as the directory number of the callingsubscriber is registered in the database in thenetwork node of the alternative provider (i.e.within an service switching point, SSP). In addi-tion the calling subscriber can be identified via anauthorization code (see also calls with identifica-tion). Depending on the authorization codes en-tered in the database, subscribers can also usefeatures within the network.

Travel Service

Using the travel service, subscribers of an alternativenetwork provider can use a specific service numberand authorization code to make a call from any tele-phone or PBX from any network via the carrier’s net-work.

Subscribers wishing to set up a call via the network ofan alternative provider first dial a service number (e.g.Freephone service number 800). They then hear a sec-ond dial tone requesting them to use DTMF to enter anauthorization code for identification. In this case thecalling subscriber number is not registered in the net-work node.

Depending on the authorizations entered in the data-base, subscribers can also use features within the net-work.

After successful identification the subscriber hears asecond dial tone requesting entry of the destinationnumber.

Features in EWSD transit networknodesUsing the services "Dial Up Access" and "Travel Ser-vice" the features described below can be implementedin transit network nodes for voice calls.• Dial up access

– Barring of Destinations– Follow on Calls– Individual Traffic Restrictions

• Travel service– Barring of Destinations– Follow on Calls– Individual Traffic Restrictions– Abbreviated Dialing– Fixed Destination Call– Fraud Prevention

Travelservice

EWSDtransit

networknode

Alternativeprovider’snetwork

Callingsubscriber

Lo-calnet-worknode

Service numberauthorization code

4

For these services subscribers can be connected di-rectly or indirectly to the network of the alternative pro-vider. The subscriber is identified via the individualaccess (administrated in the network node of the alter-native provider) or via an authorization code or person-al identification number (PIN).

To identify the directory number of the calling subscrib-er the signaling interface of the local network nodemust allow the number of the calling subscriber to betransmitted to the network node of the alternative pro-vider.

Barring of Destinations

With feature Barring of Destinations customers of an al-ternative network provider can define up to 50 directorynumbers for their access for which a connection tothem is either allowed or not allowed. Specification ofpartial directory numbers is also allowed.

Subscribers can use this service in its functionality as“White list” or as “Black list”.– White list

Calls can only be set up to called subscriberswhose numbers are explicitly entered in this list.

– Black listCalls to called subscribers whose numbers are ex-plicitly entered in this list are rejected.

Alternative provider’snetwork

Calledsubscriber

2345

EWSDtransit

networknode

Directory number 1234:allowed!

Directory number xxxx:allowed!

or

White list

Directory number 2345:barred!

Directory number 3456:barred!

Black list

STOP

Callingsubscriber Local

net-worknode

Localnet-worknode

Localnet-worknode

1234

1

n

5

Follow-on Calls

With feature Follow-on Calls subscribers only need dialinto the network of an alternative provider once to en-able them to set up a number of calls in succession viathis network.

The new call can be set up if the called subscriber wasnot reached, when the called subscriber has replacedthe handset after a successful call or after the call hasbeen released by the calling subscriber using the mid-call trigger.

Individual Traffic Restrictions

With the feature Individual Traffic Restrictions custom-ers of an alternative network provider can bar specificdestinations (e.g. specific countries) or destination ar-eas (e.g. intercontinental) for their access.

Alternative provider’s network

Calledsubscriber

EWSDtransit

networknode

Callingsubscriber

Localnet-worknode

Localnet-worknode

1

n

Localnet-worknode

Alternative provider’s network

EWSD-Transit-

Netz-knoten

Callingsubscriber

Localnet-worknode

Localnet-worknode

STOP

Localnet-worknode

Country Y

Country Z

Localnet-worknode

Country A

6

Abbreviated Dialing

The feature Abbreviated Dialing allows customers of analternative network provider to set up a call to a partic-ular subscriber by dialing an individual abbreviatednumber. The stored abbreviated numbers can be num-bers for national and international calls.

Fixed Destination Call

The feature Fixed Destination Call allows customers ofan alternative network provider to set up a call immedi-ately or after a preset delay to a previously defined des-tination, simply by lifting the handset. If the callingsubscriber begins to dial a different subscriber numberwithin the delay time the feature does not become ac-tive.

Alternative provider’s network

Calledsubscriber

EWSDtransit

networknode

Calling subscriber 1:Abbr. number: 11

Calling subscriber 2:Abbr. number: 12

Callingsubscriber

Localnet-worknode Local

net-worknode

1

n

Calling subscriber n:Abbr. number: xx

Localnet-worknode

Alternative provider’s

network

Calledsubscriber

Callingsubscriber

EWSDtransit

networknode

Lo-calnet-worknode

Lo-calnet-worknode

7

Collect Account Code

The account code can be used for identification in ad-dition to the directory number of the calling subscriberand/or the authorization code. It is used primarily inpostprocessing for charge accounting.

The account code can be validated or non-validated:– Validated Account Code

MML can be used to administrate a list of up to 512account codes (2 to 12 characters) for the callingsubscriber number or for their authorization code.In this case the calling subscriber enters the ac-count code (except when making follow-on calls).With a follow-on call the calling subscriber can alsoenter a different account code. If a subscriber doesnot enter any code, he/she must press the "#" but-ton instead and the previously entered accountcode is written into an IN-AMA data record. Thesystem checks the dialed account code and deter-mines whether the call can be continued.

– Non-validated Account CodeThe dialed account code is not checked by the sys-tem. Despite this the length of the account code canbe administrated and is used to establish the end ofentry for this account code. The account code iswritten into an IN-AMA data record as for "ValidatedAccount Code". If the calling subscriber does notenter any account code, he/she must press the "#"button instead. In this case no entry is made in anIN-AMA data record.

Fraud Prevention

The feature Fraud Prevention prevents hackers fromfinding out authorization codes. The directory numberof the hacker is identified and barred for further activi-ties in the transit network node.

The hacker’s directory number and the wrongly dialedauthorization code are recorded. Every subsequent un-successful attempt by the hacker is also recorded.

The threshold value for the number of unsuccessful at-tempts and the time between the unsuccessful at-tempts can be administrated.

When the threshold value for unsuccessful attemptshas been reached,– the directory number is entered in the “black list” of

the transit network node and,– when the alarm output is activated, an alarm mes-

sage is displayed on the NetManager.

When the hacker’s directory number is entered in the“black list” of the transit network node, the hacker isbarred for further calls.

The message on the NetManager contains the directo-ry number of the hacker, the incorrectly dialed authori-zation codes, the date and the time.

1234

Wrongauthori-zationcode

Alternative provider’s

network

EWSDtransit

networknode

DIrectory number 1234:barred!

DIrectory number 2345:barred!

Black list

STOPLo-calnet-worknode

8

Call setupThe example of call setup described below shows howthe service works using a connection with identificationvia the calling subscriber’s directory number.

The calling subscriber dials the entry number of the al-ternative network provider followed of the called sub-scriber’s number (1).

The CP determines the appropriate trigger profile forthe incoming call and sends the information about thecalling subscriber, including the complete trigger data,to the Call Control Function (CCF) (2).

The received trigger data, the available informationabout the calling subscriber and the destination of thecall are sent from the Call Control Function (CCF) viathe Service Switching Function (SSF) and the Transac-tion Capabilities Application Part (TCAP) to the internalService Control Function (SCF) (3).

If a further entry is required, the SCF initiates a menu-driven interactive dialog to receive further data. This di-alog is implemented via the User Interaction LTG (UI-LTG) (4).

The SCF requests the service data from the ServiceData Access Function (SDAF) in the CP (5).

The SDAF, in turn, requests the necessary data fromthe Service Data Function (SDF) and sends it back tothe SCF (6).

The received data is sent from the SCF via the TCAPand the SSF to the CCF (7).

Finally the connection to the dialed directory number isset up (8).

LTG

CCF SSF TCAP

3 3

7 7

8

5

SCF

3

7 6

CP

SDAF SDF

6

6

84 4

LTG

1

2

8

Calledsubscriber

Callingsubscriber

4UI-LTG

9

Capacity

Up to 1 million subscribers can be created for eachnetwork node.

Call charge registrationFor “casual calls without identification” an AMA datarecord is created.

For the other types of call (calls with identification viathe directory number of the calling subscriber with/with-out access code) one IN AMA data record is createdper call section.

Output of AMA data records for unsuccessful calls canbe prevented for the public network by MML, for switch-based IN by means of a patch.

AdministrationThe operator can perform all administration functionson the NetManager by means of user-friendly applica-tions or MML commands.

Service authorization

The network operator assigns authorization for the ser-vice when requested by the subscriber.

Call charge registration

The charges for service usage can be administrated.

For information on call charge administration please re-fer to OMN:EXCH-TA.

System administration

The following service/feature data can be administratedin transit network nodes:– Service data– Registration by traffic measurement

For information on system administration please referto OMN:EXCH-SY.

Subscriber administration

Authorization for the service has to be assigned.

For information on subscriber administration please re-fer to OMN:EXCH-SU.

Technical DataEWSD Based IN Services in Transit Network Node canbe created when an internal Service Control Function(SCF) and a Service Data Function (SDF) are avail-able.

Hardware for user dialogs

Voice Processing Unit (VPU)

Operationally Controlled Equipment for Announcement (OCANEQ)

Signaling

between the network nodes:

Multifrequency code (MFC), including calling subscriber’s numbertransmission

Signaling System No. 7 (SS7)

subscriber signaling:

Analog: Dual-tone multi-frequency (DTMF)

ISDN: Signaling System No. 1 (DSS1)

Subscriber interfaces

the following interfaces for subscriber access are required:

Digital line unit (DLU)

Line/trunk group (LTG)

V5.1 interface

V5.2 interface

Copyright (C) Siemens AG 2002

Issued by Information and Communications Group • Hofmannstraße 51 • D-81359 München

Technical modifications possible. Technical specifications and features are binding only insofar as they are specifically and expressly agreed upon in a written contract.

Order Number: A30828-X1160-D305-1-7629 Visit our Website at: http://www.siemens.com