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August 1999


Lior, Meet Lior

I read Gatekeepers — Conducting the IP Symphony in the February 1999 issue with a great deal of interest. I am still interested to know about VocalTec Ensemble Architecture (VEA) from the redundancy point of view. What would happen if one of the components failed? Does increasing the number of components in the network not actually decline the reliability of the whole system?

Lior Gdalyahu

We decided to go straight to the source: VocalTec’s co-founder, Lior Haramaty, responds:

To prevent system failure, additional components that can perform the same functionality as existing system components, are added for redundancy, to enable the automatic replacement of a faulty component, with no or minimal system down time. The likelihood of both the main component and the redundant component to fail at the same time is very low.

Statistically, adding more components to a system increases the chance of having a component failure, but if some of the components are redundant, it decreases the chance of a system failure. For instance, by adding an additional hard drive that is a complete duplicate of the main hard drive provides a backup solution in case the main hard drive fails. Having a backup prevents system down time even though it introduces an additional component into the network that could fail by itself.

A very important issue when having system redundancy with such automatic fail-over mechanisms, is to have the right alarms to indicate a component failure. Lack of an alarm mechanism can mean that the faulty component will not be replaced (remember — the system is still functioning correctly due to the redundant system architecture), and that the system has no redundancy left — so if the backup component fails, the system will go down without the ability to recover.


A Fan of Fax

A business associate of mine in Spain told me earlier this year that his company, a small international telecom reseller, did not want to sell fax services because they concluded that fax will go away and e-mail will replace it.

The fact is that fax-to-e-mail services are indeed growing very fast but standalone fax machines are not going away anytime soon.

Dataquest recently reported that it will take years for the fax over e-mail services to overtake or even catch up with standalone fax machines. In the USA, there are currently over 20 million fax machines and this is expected to continue to grow rapidly.

According to a Dun and Bradstreet report, 42 percent of businesses use e-mail in USA; 39 percent use voice mail; BUT an incredible 65 percent use fax machines.

Internet fax traffic, an application that is slow to grow in many countries, due to an inability to market the service, is now expected to grow from 380 million pages in 1998 to 1.6 billion pages in 1999.

Long live fax!!
Ed Kennedy


Cable Security Woes

The article "Cable: A Brilliant Broad(band) Horizon" in the 5/99 INTERNET TELEPHONY´┐Ż issue fails to mention the security problems, which make cable modems unusable. Only in your article, "xDSL. Cable. Broadband Wireless.." in that same issue does one responding vendor mention that serious flaw.

This problem needs to be clearly pointed out to readers. I am sure that there is not one individual out there who wants others to be able to monitor their activity on the Web, and worse, to be able to access their computer directly. I am very surprised that security is not mentioned more. It seems that when it is, everyone is strongly advocating the strongest possible security measures. But when it comes to cable modems, it just doesn’t seem to matter.

When viewed from a security angle, cable modems become unusable. However you didn’t mention that, nor did you give any ways that this most serious breach can be fixed. If it can’t be fixed, it can’t be used. It really is as simple as that. Please warn people not to use them.

Michael Kitchen







Technology Marketing Corporation

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