For most this is not an issue when they have high speed internet access, however, it can become a problem with satellite links or any other system where unusually long distances and many hops are involved.

On private networks, there is rarely a problem using VoIP and many companies with internal networks (such as telcos and power companies) use VoIP to communicate within their organizational network structure.

However, when available end-to-end bandwidth is less than 256 Kbps, a good VoIP system will require mechanisms to overcome fragmentation of data stream.

Security is an issue everywhere on internet and what this means is that VoIP also needs to deal with firewalls and NATs (Network Address Translation). While some systems can do NAT and firewall traversal on their own, others require use of SBCs (Session Border Controllers) to manage traversal.

One major, though non-technical, challenge to VoIP, comes from traditional telephone service providers who are being by-passed by consumers who love extremely low (or zero) long-distance charges they can get by using VoIP. Exactly how this works out over long run will be fascinating to watch. In meantime, VoIP services are continually being improved and extended. Enjoy them.

For more on VoIP, conference calling, web conferencing and more visit http://www.AltaGlobal.com. Find more on wireless and cellular subjects at http://www.AltaGlobal.org. For networking and security check

Almost at same time with appearance of first Trojan for PDAs, first virus to affect cell phones has also arrived. This worm is called “Cabir”, and it has been spotted by some security specialists who issued an alert concerning danger. Cabir spreads using a file named “Caribe.sis” and travels across devices working with Symbian operating system which is used in PDAs and many cell phones. Cabir places itself usually on a mobile device when a user agrees to a transmission showing text message "Caribe". After that worm begins a nonstop search particularly for Bluetooth-connected wireless devices to send itself to. Also, battery’s life of infected device is harshly reduced during this process. The inventors of Cabir did not design worm to spread massively. It was intended to be a test demonstrating that these mobile devices can be easily infected by viruses because of their rapid maturation. The worm rated with a low risk because it has to be intentionally activated by a mobile phone user, and also allowing Caribe package requires pressing a button prior files can be loaded into receiving phone.

It was predictable that viruses and worms for cell phones and PDAs would appear. This is end result of impressive advances made in mobile communication technology in past years. Over time, cell phones and PDAs turn out to be more PC-like, making them vulnerable to viruses. And because they are more PC-like, smart cell phones and PDAs are mostly used by companies for mission-critical applications and data storage. Also they are used for receiving emails and text messages just like desktop computers. That makes their users just as exposed to viruses and worms. These security concerns can be dealt with software-encryption solutions that need to be attached to new devices. The encryption technology expands to mobile devices identical type of security that many companies have organized into their desktop computers. It encrypts data and prevents illegal access to data stored within device, which is either lost or stolen.