PCE SS7 Configuration

The Basic PCE manages SS7 traffic between the public and private network. The Enhanced PCE manages this traffic between the public and two private networks.

PCE supports ISUP traffic for trunk mapping and/or TCAP traffic for transaction identifier mapping. You can configure the supported traffic using the PCE General Configuration user interface (see Initial PCE Configuration Tasks).

PCE interfaces with the following STP components:

Message Transfer Part Level 3

MTP3 manages internetwork traffic, and, with the definitions of VNodes, allows the PCE to intercept cross-network traffic. You must define VNodes in the private NA for the relevant public node’s corresponding private network PCs (see the following figure). For Enhanced PCE, the private MTP3 must also include VNodes for the alternate private PC. In addition, you must define VNodes in the public NA for the corresponding public gateway PC(s).

VNodes for PCE Deployment

Transfer messages (TFMs) are processed locally. The cross-network notifications of TFMs are unfeasible due to the many-to-one private nodes to public gateway mapping.

In MTP3, if the reserved DSC_DEFAULT_RS Application ID is registered and the received MSU has no associated active routeset or VNode for that DPC, the MSU is forwarded to the registered Application ID. The PCE registers the DSC_DEFAULT_RS Application ID to the private network SCCP NA (or NAs for Enhanced PCE) when the PCE Non Member Routeset Support attribute is set to ENABLED. In this configuration, the MTP3 responds to routeset test messages with the associated TFA/TCA messages to indicate destination availability. If the DSC_DEFAULT_RS Application ID is not registered, standard MTP3 error handling is applied for an unavailable destination. For more information about Application IDs, refer to Reserved Application IDs for SS7 Applications.

Signaling Connection Control Part

The Signaling Connection Control Part (SCCP) manages the TCAP messages transfer to PCE.

SCCP processes SCCP Connection Management Messages (SCMGs) locally. Because of the many-to-one mapping of private nodes in the private network, SCMGs are not feasible, similarly to the TFMs at MTP3. Received SST messages are replied to with an SSA if the PC is registered (full SSNs range). The actual state of the SSN in the other network is not taken into consideration. If a destination’s subsystem number (SSN) is unavailable, the resulting Unitdata Service (UDTS) is returned to the originating network.

PCE does not support SCCP Connection-Oriented messages.These messages are transferred through a connection identifier that cannot be mapped between the public network and the private network NAs.

Global Title Translation

The Global Title Translation (GTT) may be used to route the TCAP transactions initiated by the public network to the private network and the TCAP messages destined for PCE GTT tunnelling.

If GTT routing is required on any of the PCE NAs, set the GTT NA Connection Type to PCE for associated GTT NA creations.