Avamprogetto 2b
Consultazione 2017/22: Progetto di legislazione esecutiva relativa alla revisione totale della legge federale sulla sorveglianza della corrispondenza postale e del traffico delle telecomunicazioni · 34 pagine
Fedlex · Progetto · Pagina 23Fedlex · Progetto
11 Signalling sequences for the CS delivery network The following diagrams show signalling sequences at both handover points from the CSP to the ISDN-DN provider (ISUP sequences) and from the ISDN-DN provider to the PTSS (DSS1 sequences). Figure 22 shows a successful and complete delivery of CS-CC.
Area of responsibility of CSP nonnon --coincidentcoincident
LEMF MDMDMD LILI--HPHP
Access LineAccess LineAccess Line
GWGWGW LELE NTNTNT
DNDN--HPHP
MD hosting facility DN ProviderDN ProviderDN Provider DN ProviderDN ProviderDN Provider Area of responsibility-
FacilityFacilityFacility FacilityFacilityFacility of PTSS Area of responsibility of ISDN-- DN provider
InitialInitialInitial AddressAddressAddress MessageMessageMessage (IAM)(IAM)(IAM) SETUPSETUPSETUP MessageMessageMessage AnswerAnswerAnswer MessageMessageMessage (ANM)(ANM)(ANM) CONNECTCONNECTCONNECT MessageMessageMessage TargetTargetTarget ‘‘’sss CommuniCommuniCommuni --- CCCCCC ---linklinklink cationcationcation ReleaseReleaseRelease MessageMessageMessage (REL)(REL)(REL) DISCONNECT/RELEASEDISCONNECT/RELEASEDISCONNECT/RELEASE MessageMessageMessage
ReleaseReleaseRelease CompleteCompleteComplete MessageMessageMessage (RLC)(RLC)(RLC) subsequentsubsequentsubsequent Messagesmessages accordingaccordingaccording to ITUto ITUto ITU ---T Rec. Q.931T Rec. Q.931T Rec. Q.931
ttt
Figure 22 Signalling sequences for the required set-up and release of a CC link The ANM is a form of acknowledgment for the CSP (received by the MD) that a CC link has been set up and the delivery of CC is starting. After the intercepted connection is released, the CC links are also released by the MD and the LEMF receives a REL with cause value 16 and the location “user” (0000). Figure 23, Figure 24 and Figure 25 show unsuccessful attempts to set up a CC link. The MD will repeat the connection set-up attempts a specific number of times (not shown in Figure 23, Figure 24 and Figure 25).
Area of responsibility of CSP LEMF site non -coincident
LEMF
MDMD LI-HP Access Line
GWGWGW LELE NT
DN-HP MD hosting Facility DN ProviderDN Provider DN ProviderDN ProviderDN Provider
FacilityFacility FacilityFacilityFacility Area of responsibility-
Area of responsibility of ISDN- DN Provider
Initial Address Message (IAM) Release Message (REL)
Target's failed
Communi-
cation Release Complete Message (RLC)
t