When the information technology department plans for upgrades, especially a VoIP deployment, a lot of attention is focused on servers, applications, switches, routers, and network security. Just about no attention is paid to the core network services that provide users access to all these splendid systems, and are in all cases essential for VoIP to even work at all.
If users are unable to get to the applications that they need over the network, or if customers are unable to access the Internet-based Web services or applications that they need, all business transactions come to an immediate stopping point . Since application access is so necessary, it is worthwhile to look at how to make sure everything in the system works properly.
There are four core network services that have to be up and running for users to be able to get to their applications. These are:
- DHCP stands for Dynamic Host Configuration Protocol. This service is what gives the user an IP address on the internal network when they connect. No network communication can happen without having an IP address, as well as the other information that the DHCP service provides, which is a default route and the IP addresses of the DNS servers. What most people don’t know is that most often the DHCP service is handled by a non-redundant Windows box , or by a router that provides almost no visibility into the operation of the service. DHCP is necessary for VoIP systems.
- DNS stands for domain name service. This service is what changes simple to remember names on the network, like a URL in an application , to the IP addresses that the applications running on computers can’t do without . Without DNS, any network-based applications cannot be used. DNS is most often provided centrally by redundant windows servers, and externally by multiple small Linux boxes running BIND. Unfortunately, sometimes the Windows DNS service has stability issues, and it is tedious and error prone to change the BIND settings on the Linux boxes.
- NTP stands for network time protocol. There are many applications that need the correct time on the servers and workstations, especially SIP-based voice applications and network security programs . NTP is in most cases served from redundant windows servers.
- IPAM stands for IP address management. It is important to have an overall IP address organizing method in order to ensure that DHCP and DNS are working properly. Entire new subnets are added in a VoIP deployment, so this is especially high priority then.
As you should be able to see, high availability core network services are a very important to the correct operation of everything on the network, and especially VoIP. In your next upgrade planning cycle, it is beneficial to look at upgrading the availability of the core network services of DHCP, DNS, NTP, and IPAM.