Projet 2b
Consultation 2017/22: Projets d'ordonnances pour la mise en œuvre de la nouvelle loi fédérale sur la surveillance de la correspondance par poste et télécommunication · 34 pages
Fedlex · Projet · Page 23Fedlex · Projet
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