Cisco Systems OL-1089-11 manual Cisco MGC Clock Synchronization, Detailed CDB Description

Chapter 1 Billing Interfaces

Cisco MGC Clock Synchronization

If a call was stable during the failover, then the newly active Cisco MGC eventually generates an end of a call CDB (Release CDB or possibly an Interrupted CDB) for each call. The CDBs generated by the previous standby MGC include the same unique Call IDs. The mediation software requires correlating the CDB records from both systems. For both systems to be properly correlated, both Cisco MGC clocks must be synchronized with each other.

Cisco MGC Clock Synchronization

The Cisco MGC uses Network Time Protocol (NTP) to synchronize its time to another server or reference time source, such as a radio or satellite receiver or modem. For example, the NTP provides client accuracy that is typically within 1 millisecond on LANs and up to a few tenths of a second on WANs relative to a primary server synchronized to Coordinated Universal Time (UTC) by a Global Positioning Service (GPS) receiver. To achieve high accuracy and reliability, typical NTP configurations use multiple redundant servers and diverse network paths. Some configurations include cryptographic authentication to prevent accidents or malicious protocol attacks.

Note RFC-1305 provides information on the NTP architecture, protocol, and algorithm.

Detailed CDB Description

This section contains the distinct record layouts for the CDB. Since each type of CDB is for a different part of a call, the Cisco MGC provides the related CDEs that are needed.

Note The CDE includes only fields that have values. The layout varies based on the Cisco MGC configuration. For example, if the Cisco MGC is configured with a protocol that does not support a specific CDE, then the CDB record does not include that particular CDE.

Answered CDB Record (Tag: 1010/Release 5 or Later)

Table 1-6lists data about the answered message. This CDB is generated when a call went through and was answered (when the Cisco MGC receives ANM/Answered message).

	Table 1-6	Answered CDB Record
			Tag
	Field Name		Value	Comments
				When configured for ANSI-based formatted
	ANSI Based Formatted Fields			fields (Release 7 or later option)
	Calling Party Category		2000
	User Service Information		2001
	Originating Line Information		2002
	Calling Number Nature of Address		2003
	Charged Number Nature of Address		2004
		Cisco Media Gateway Controller Software Release 9 Billing Interface Guide
OL-1089-11					1-21