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?
We decided to go straight to the source: VocalTecs co-founder, Lior Haramaty,
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!!
Cable Security Woes
The article "Cable: A Brilliant Broad(band) Horizon" in the 5/99 INTERNET TELEPHONY� 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
doesnt seem to matter.
When viewed from a security angle, cable modems become unusable. However you
didnt mention that, nor did you give any ways that this most serious breach can be
fixed. If it cant be fixed, it cant be used. It really is as simple as that.
Please warn people not to use them.