Oct 22, 2009

Connect to E911 via PRI or CAMA trunk?

There are two types of circuits an enterprise can use to route 911 calls to the proper PSAPs (public safety answering points) and deliver the 10-digit caller ID: ISDN PRIs or Centralized Automatic Message Accounting (CAMA) trunks.

"ISDN is the wea port of choice from our perspective," says Guy Clinch, Avaya's government solutions director and a member of the National Emergency Number Association's PBX/multi-line telephone system technical subcommittee, because you can fit more phone lines in a PRI and assign each of those numbers to represent a separate ERL. In short, you can map your location and send more granular location information to the PSAP.

But as many as 85% of enterprises choose instead to retrofit their IP PBXs using legacy analog CAMA trunks for entry into the public safety system, Clinch says. It's cheaper, because the CAMA trunk is equivalent to on phone number, so they get charged only once.

The downside: CAMA trunks cannot deliver a custom caller ID like PRIs can, notes Mark Fletcher, chair of the multi-line telephone system...

Oct 21, 2009

Cisco Monitor Director

Cisco Monitor Director, a centralized proactive solutions-management tool for Cisco channel partners to offer multicustomer outsourced 24-hour network management services. It communicates with the Cisco Monitor Manager residing on a customer's premises to provide comprehensive, real-time monitoring, alerting and reporting to help troubleshoot and fix issues remotely. Combining these management tools helps enable Cisco channel partners become trusted advisers to their customers.

The Smart Phone Control Protocol (SPCP)

The Smart Phone Control Protocol, or SPCS, is an addition to the Simple Call Control Protocol (SCCP) that is only supported on the CP-500 phones and the SPA525 phone.

79XX phones register with their SCCP call control using a proprietary handshake that consists of a series of messages. During the registration phase a number of things happen:

1. Phone (Station) sends a Registration Request

2. Request is acknowledged by the Call Control (CME/UC500)

3. Capabilities are advertised

4. Button template, Softkeys, Line Status, Display message, Speed dials Time and date are requested by the phone and sent by CME/UC500

When the phone is a 500 series phone, two additional messages precede all this handshake, namely an SPCP Token Request and an SPCP Token Acknowledgement (if successful) or Token rejection (if unsuccessful). A Token ACK can only be sent by UC500, while an ISR will always send a Token Reject. This prevents the phone from registering to any call control different than UC500.