RedCARE, VoIP and Porting 29/12/2010
Posted by Kevin Box on Wed, Dec 29, 2010 @ 09:38 AM
BT insists that a telephone number is allocated to an analogue line.
This means that if a number is to be ported to another provider, such as Cloudnet, then the line must be ceased. The usual way around this problem is to allocate a temporary number to the customer until the port is completed. Once the port is completed then the line can be reconnected but with a new phone number. This means that a port of an existing line requires another line to be installed before the port can proceed. This problem does not exist with cable installations and neither does it exist if a new number is acceptable.
The problem is compounded if the line is a RedCARE number. It is possible to run a VoIP installation on a RedCARE line by installing a MCD (see below). If it is not possible to install an MCD then the line cannot be used. However if you wish to port the number with RedCARE to a VoIP provider then you have to cease the RedCARE, because the line will cease. If you then want to reconnect the RedCARE to another line there is a new RedCARE installation fee which will be around £200.
These problems are not caused by Cloudnet but are inherent in the insistence of BT on a telephone number residing on a line. There is no technical reason why this should be so, however as you can see above there is a large commercial reason.
The recommendation for all users of RedCARE we believe should be to leave well alone. The savings you make by putting other services on the line – whether they are VoIP or other voice or data services will be outweighed by the grief you will suffer if the services interfere with the RedCARE technology.
For those not familiar with the RedCARE technology please see this explanatory information.
A Brief Overview of the RedCARE System
RedCARE provides continuous monitoring of an alarm installation by means of an inaudible signal (Modulated Low Tone or MLT) which is present on the line at all times when the RedCARE transmitter (STU) located at the protected premises is in the "UP" condition. MLT is critically monitored by means of a RedCARE "Scanner" installed at the end-users local telephone exchange. The Scanner, for additional security, periodically communicates with the STU by means of audible, routine polling tones (Polls or Chirps) every 120 seconds. These polls, which require a response by the STU, are complex, encrypted message "packets" comprising
information relating to the status of the alarm installation. To prevent compromise, the Scanner expects a poll response from the STU, which is unique to each end-user.
In addition to providing continuous monitoring of the alarm system, the MLT signal is processed by the Scanner to determine whether the end-users telephone is in use (off-hook). Audible polling tones are normally suspended when the telephone line is being used.
Should an alarm occur one or more of the STUs inputs will be triggered by the detection system control panel, the STU responds by removing the MLT signal from the telephone line. In turn, a poll is immediately issued by the Scanner. In response to this poll, the STU updates the Scanner on the changes) to the status of its channels.
These changes are relayed via the Scanner and RedCARE network to the remote Alarm Receiving Centre (ARC).
Should the telephone line be cut, communication between the Scanner and STU will be lost. The Scanner will initially issue many polls to verify the communication failure. Should the STU fail to respond a "No Response" message will be forwarded to the ARC within typically 35 seconds following the line cut. For installations using RedCARE GSM, alarm system monitoring is maintained by the GSM radio link.
Telephone line specification
The RedCARE STU, connected to the telephone line at the customers premises, is an additional telecom product and therefore increases the overall Ringer Equivalence Number (REN) by a value of 1.0. As a guide a standard telephone has a REN of 1.0 unless otherwise marked. In line with BT recommendations, the total REN that can be simultaneously connected to the line should not exceed 4.0.
Data Devices
The RedCARE Modem Compatible Device (MCD) lets end-user customers connect RedCARE alarm signaling to data applications such as a PC, Digital TV or fax over the same analogue line.
RedCARE signaling can be connected to analogue telephone lines that are used for fax or data services, without the need for dedicated or additional alarm lines.
The MCD is an easy to install, plug and play solution that requires no specialised knowledge to fit and can be fitted by the end-user customer.
The MCD makes it possible to connect more than one data device through a single MCD (where practical) using a telephone socket doubler.
Where connection of the MCD is impractical, it is generally not recommended for RedCARE to share a telephone line with data applications. However, it is possible for a 3GSTU to share the same line as a V21 modem at 300 baud, although the reliability of this combination is dependent on the quality of the telephone line. Higher baud rates and other specification of modem must not share the same telephone line as a 3GSTU. An unapproved data application may corrupt the RedCARE signals resulting in spurious No Response messages to be forwarded to ARC, or perhaps more seriously, delay the transmission of an alarm activation.
Where RedCARE and data devices share a telephone line correct operation cannot be assured. The use of shared data devices is therefore at the discretion of the Alarm Installer.
Written by David Hill, Chairman, Cloudnet
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Cloudnet supplies business phone systems and services to SMEs and start-ups. Its Cloudnet Connect system offers the advantages of no capital expenditure necessary to run a professional PBX and dramatically lower running costs. Cloudnet has developed a dedicated voice over IP (VoIP) network providing free calls within its network and cheap rate calls outside of the Cloudnet network. The company also offers CLASS, a live answering service and has introduced mobile VoIP solutions. Cloudnet is privately financed and started trading in March 2009.