Isup Isup Call

Incoming ISUP and Outgoing ISUP Transit Call (ISUP to ISUP Successful Call)switching system

call handler1 central processor call handler2isup mgr1 isup call1 ts mgr1 tone mgr1 rout mgr ss mgr ts mgr2 tone mgr2 isup call2 isup mgr2

EventHelix.com/EventStudio 1.5

06-Jun-02 21:52 ()

Copyright (c) 2002 EventHelix.com. All Rights Reserved.

This Message Sequence Chart describes an ISUP (ISDN User Part) call. The call is incoming ISUP and after routing it is sent out on an ISUP trunk

Call incoming on ISUP

iam IAM (Initial Address Message) in ISUPreceived for Incoming Call. The IAM messagecontains some of the digits for the destinationsubscriber.

allocateIncoming Trunk

ISUP manager allocates incoming trunkresource for call

create ISUP manager creates ISUP call object tohandle the incoming call

iam Information of the incoming call is passed on toISUP call object in IAM message

sam SAM (Subsequent Address Message) in ISUPreceived from previous exchange. Thismessage contains more digits received at theincoming end.

sam SAM with ST condition received from previousexchange. This signifies that the last digit of thedestination subscriber address has beenreceived.

resource_allocate Send Resource Request for space slotallocation

interfacerouting

Call Outgoing on ISUP detected after routing

allocatePath

Space slot manager allocates path resource forcall

resource_allocate_ack Resource response containing t-s-t resourcesfor call received

interfaceswitch

Switch the path for call

interfaceswitch

Perform t-s switching for call

interfaceswitch

Perform s-t switching for call

beginSwitch Path

call_request Send call request to outgoing call handler

allocateOutgoing Trunk

ISUP manager allocates outgoing trunkresource for call




06-Jun-02 21:52 ()

create ISUP manager creates ISUP call object tohandle the call outgoing on ISUP

call_request Information about the call is passed to the callobject in call request message

call_request_ack

iam Send IAM with ST condition in ISUP to nextexchange. The ST condition means that all thedigits required for routing the call are containedin the IAM message itself. No SAM messageswill be required for sending subsequent digits.

tacm Outgoing ISUP call object awaits ACM(Address Complete) message from nextexchange

crg Charging information received in ISUP fromnext exchange

crg Charging information is relayed backwards

crg CRG sent to previous exchange

LEG: Outgoing call through acm Subscriber free indication received in ACM

(Address Complete) message.tacm Stop ACM timer

acm Called subscriber free indicated to incomingcall handler

acm Subscriber free indication sent in ACM toprevious exchange

tans Start answer, ANS timer

ans ANS received in ISUP from next exchange

ans ANS indicated to incoming call handler

tans Stop ANS timer

answer_ack

ans ANS sent to previous exchange

Call is in CONVERSATION

LEG: Call release received from called side rel ISUP REL (Release) message received from

the next exchangerlc ISUP RLC (Release Complete) sent to the next

exchangecall_release Call release indicated to incoming call handler




06-Jun-02 21:52 ()

call_release_ack

call_over Send call over indication for outgoing call

delete

freeOutgoing Trunk

ISUP manager frees outgoing trunk resourceallocated for call

resource_free Release t-s-t resources allocated for call

interfaceunswitch

Release t-s switching done for call

interfaceunswitch

Release s-t switching done for call

endSwitch Path

freePath

Space slot manager frees the path resourceallocated for call

resource_free_ack

rel REL in ISUP sent to previous exchange

trlc Start RLC timer

rlc RLC in ISUP received from previous exchange

trlc Stop RLC timer

call_over Send call over indication for incoming call

delete

freeIncoming Trunk

ISUP manager frees the incoming trunkresource allocated for call

Isup Isup Call

Documents

Transcript of Isup Isup Call