Replacing the telephone company with VoIP comes with one major potential problem for companies: The Internet is simply not as reliable as landline telephones. "There are going to be problems, and times when things go down," says Will Stofega, an analyst at IDC (a sister company to CIO\u2019s publisher). "How you react to it is critical."Especially if you are a CIO at a mid-market or smaller company, you may be pressed for disaster-planning resources, but don\u2019t skimp, say CIOs who\u2019ve been there. Marty Resnick, director of technology operations at Norman\u2019s Nursery, made disaster recovery planning central to his VoIP planning. He made sure that there were still working analog lines at each facility, in case of network and power outages. He also made sure that if a single VoIP server crashed, the phones would roll over to a server at another location.IDC\u2019s Stofega gives these tips for other CIOs planning for the worst while working toward the best:After network testing, upgrade routing software where necessary and make sure it\u2019s as bulletproof as can be.Consider setting up a virtualized LAN or having a backup location for VoIP.Bolster security safeguards to fend off denial-of-service attacks and other Internet-clogging events.Write a careful plan for an actual emergency\u2014including who should be called, who should be onsite and who should call your provider.