Frequently Asked Questions

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Overview

The following questions and answers address common issues related to SS7 over the ring.

Questions

How does the 50-second delay at start-up affect operation of SS7 Over the Ring?

The 50-second delay is a one-time delay during initialization only. It occurs when the host sends a CCS Redundancy Configure (0x5B) message and waits for the ACK, which takes 50 seconds. See also the CCS Redundancy Configure message in the API Reference, which adds this note: "Cantata highly recommends that, when you configure SS7 redundancy, you send this message first, followed by all other SS7 configuration messages."

How is synchronization affected if configuration is attempted before the delay is complete?

The host cannot and should not attempt to perform any other SS7 configuration until synchronization is finished. This is no different from the current implementation of SS7 redundancy.

Are there any limitations for PPL-related actions on the CSP? What happens, for example, when the PPL Event Request has to address voice circuits where they reside, on the remote node?

For all PPL-related API messages that use an AIB addressing the logical span and channel of an SS7 CIC, the Logical Node ID field MUST indicate the node ID of the node on which the CIC resides.

The PPL API messages affected are as follows:

• PPL Event Request 0x44

• PPL Timer Configure 0xCF

• PPL Configure 0xD7

• PPL Assign 0xD1

• PPL Data Query 0xDE

• PPL Audit Query 0xDD

The API messages mentioned previously are affected when they are paired with one of the following SS7 CIC-based components:

SS7 Components
0x0F L3P_CIC 0x14 ISUP_CCI 0x17 ISUP_BLR 0x1A ISUP_UCIC 0x1D ISUP_GBUS 0x42 ISUP_HLB 0x45 ISUP_MGBS 0x76 ISUP_CQS 0x79 ISUP_CVR 0x82 ISUP_DCO 0x54 TUP_BLR 0x57 TUP_CRI 0x5A TUP_CGRS 0x5D TUP_HBUS 0x60 TUP_SBUR	0x11 L3P_TUP 0x15 ISUP_CRI 0x18 ISUP_CRS 0x1B ISUP_CGRS 0x1E ISUP_GBUR 0x43 ISUP_HRB 0x46 ISUP_MGBR 0x77 ISUP_CQR 0x80 ISUP_CCO 0x83 ISUP_CRO 0x55 TUP_BLS 0x58 TUP_CRS 0x5B TUP_MBUS 0x5E TUP_HBUR 0x12 ISUP_CPC	0x16 ISUP_BLS 0x19 ISUP_CRR 0x1C ISUP_CGRR 0x1F ISUP_HGBR 0x44 ISUP_CRCR 0x47 ISUP_HGBS 0x78 ISUP_CVS 0x81 ISUP_CRCS 0x52 TUP_CPC 0x56 TUP_CCI 0x59 TUP_CGRR 0x5C TUP_MBUR 0x5F TUP_SBUS

For any other combination of PPL-related API messages and SS7 PPL components, the Logical Node ID field must be set to the node ID of the SS7 server node.

In general, if an SS7 CIC is being addressed, the Logical Node ID field should indicate the location of that CIC. If any other object is being addressed (for example, slot, SS7 link, route), the Logical Node ID field should indicate the SS7 Server Node.

All PPL Event Indications from one of the above components will contain the Logical Node ID of the node on which the CIC resides.

How does redundancy operate in SS7 Over the Ring?

From a host software standpoint, SS7 over the ring redundancy operates in exactly the same manner as the current implementation of SS7 redundancy.

Does SS7 Over the Ring require an IP address on the card?

No. With SS7 over the ring, the SS7 card communicates using a Cantata proprietary protocol that is similar to a UDP and which does not use an IP address. The host does not need to communicate with the card directly for any reason. The Ethernet connectivity on SS7 over the ring enables the SS7 card to communicate with the Matrix Controller cards on remote nodes where the CICs reside.

When CSP receives the undefined Protocol message from adjacent CSP, what does CSP do?

CSP will reply UPU message, send PPL indication "UPU MSU transmitted" (PPL 0x2C, ID 0x06) and discard the message.

When CSP receives the undefined ISUP Messages from adjacent CSP, what does CSP do?

CSP will reply with a CFN message with Cause 97 (message type non-existent or not implemented), send PPL indication "Undefined message received" (ppl 0x13, id 0x03), and discard the message.

When CSP receives the undefined Parameters in ISUP Message form adjacent CSP, what does CSP do?

CSP will reply CFN message with cause 99 (information element non-existent or not implemented), and send PPL indication "parameter discard" (ppl 0x12, id 0x4e) and continue the message without this undefined parameter included.

What is the maximum number of CIC groups that can be created per node?

128

FYI:

ITU defines MCP and PCP for undefined messages and parameters. MCP and PCP messages provide support for unrecognized signaling as defined by ISUP 1992 (ITU-T White Book). This support becomes necessary, for example, if the exchange receives unrecognized signaling information from a later version of ISUP. With MCP/PCP, the exchange can take the appropriate action and ensure its compatibility with new signaling messages, no matter which version they may be.