How does a VoIP phone work?

Posted By: technopediasite



VoIP phones, also known as IP phones, include features and capabilities not found in traditional analog phones. They also have additional performance requirements because phone calls are placed over the internet instead of the legacy public switched telephone network (PSTN).

The average VoIP phone isn't that much different from the analog phone you currently have at your desk. VoIP phones look the same, and often have the same features, as the landline desk phones you're probably familiar with.There are, however, some key differences that distinguish VoIP phones from other desk phones. This blog will give you a quick overview of how a VoIP phone works and how to use one.

How does a VoIP phone work?

Some VoIP phones require A/C adapters for power, while others use Power over Ethernet(PoE). PoE uses an Ethernet cable instead of an A/C adapter and removes the need for separate power and data cables.

Phones are assigned IP addresses through the Dynamic Host Configuration Protocol (DHCP), which automatically configures the network and the VoIP parameters. A domain name system (DNS) tracks the IP addresses to enable devices, such as IP phones, to connect to each other.

VoIP phones require a number of protocols to facilitate the delivery of voice communications over the internet. H.323 is the most commonly used VoIP protocol that supports audio, video and data communications across IP networks. It provides several VoIP functions, including bandwidth management and call control.

VoIP phones, on the other hand, do not have "lines" in the traditional sense. Instead of being tied to a phone number, each 'line' on a VoIP phone is tied to a SIP address, or user account. Depending on your phone model, your phone may be able to handle multiple user accounts simultaneously. This means you can take calls from multiple accounts and different phone numbers on your VoIP phone.

Session initiation protocol (SIP) is a signaling protocol that sets up VoIP connections and is used as an alternative to H.323. Real-Time Transport Protocol (RTP) is used to send and receive multimedia information between two devices. VoIP services use RTP and SIP or H.323 to stream multimedia content. The Simple Traversal of UDP through NAT (STUN) protocol is used on some SIP-based VoIP phones to enable communications behind network firewalls, which can sometimes block SIP and RTP packets.

Advantages and disadvantages of VoIP phones

➤Organizations can reduce calling costs by switching to VoIP services. While traditional analog phones can have lower upfront costs, they are more costly to support, upgrade and integrate with communications applications. IP phones also offer cheaper long-distance and international calls, as VoIP phone calls are charged at the local rate of the call's destination.

➤VoIP phones offer greater mobility and scalability than traditional handsets. If an organization moves to a new location, it doesn't need to acquire new phone lines, which it would with a traditional phone system. Adding new phones to a VoIP system is only limited by the available bandwidth on the organization's network. Softphones also provide increased mobility, as the clients are not tied to physical locations like they would be with hard-wired phones.

➤VoIP phones can also integrate with other communications applications. For example, organizations can integrate their customer relationship management (CRM) software with VoIP phones to enhance caller ID and keep records of call information.

➤VoIP phones, however, do have disadvantages. For example, VoIP phones require a reliable internet connection and are susceptible to bandwidth constraints. With insufficient bandwidth, phone calls may experience latency, which can result in delays and dropped calls. Additionally, if an organization has a power or internet outage, users cannot make calls from their VoIP phones.

➤Emergency calls with VoIP phones can be difficult because IP addresses do not offer the exact location of callers, which makes it difficult for 911 operators to route VoIP phone calls to the appropriate emergency call center. VoIP providers are required by the Federal Communications Commission to support E911, however, and may use third-party providers to meet that requirement.