These companies also specialize in inter-country agreements with other phone companies in other countries. They generally don't provide local service, but often specialize in selling long distance service to residential customers. This is an individual or company, not affiliated with a local telco, who installs phone systems. They may sell systems themselves or install others that businesses may purchase themselves. This is a company that typically sells new phone systems, usually to installers or agents, for resale to organizations.
Dealers can also offer extended warranties, and can arrange consulting and installation services.
Dealers also may act as telco agents. This is a company or individual that typically buys and sells used phone systems and phones, mainly from and to installers and agents. Generally these organizations work with agents, installers, dealers and brokers to obtain and sell used phone systems. When you start to get bids for phone service, you may be surprised by the number of services you need to get. Here's a list of the usual suspects.