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What is a SIP Phone?

SIP Phone

If your business is new to VoIP systems, you probably wrinkle your brow at unfamiliar terms like “SIP phone.” Session Initiation Protocol has quickly become a hot topic amongst IT niches, but if it sounds alien to you, this guide belongs in your VoIP arsenal.

Learn what SIP means, how SIP phones differ from their VoIP counterparts, their benefits, and how to choose a suitable device.

What is a SIP Phone?

A SIP phone is a communication device or application that uses the Session Initiation Protocol (SIP) to make voice and video calls over the internet. SIP is a signaling protocol that initiates, maintains, and terminates real-time communications.

Unlike traditional landline phones that rely on analog signals, SIP phones utilize digital signals to transmit voice and data packets over the Internet. This technology is part of the broader category of Voice over Internet Protocol (VoIP) services, which allows users to make phone calls using their internet connection instead of traditional telephone lines.

What’s the Difference Between a SIP Phone and a VoIP Phone? 

A SIP phone is a type of VoIP phone that specifically uses the SIP protocol for call signaling and control. However, there are VoIP phones that might use different protocols, and they are still considered part of the VoIP ecosystem. 

SIP has become the most prevalent protocol for VoIP communications, and many modern VoIP systems and phones are SIP-compatible.

Types of SIP Phones

There are two primary types of SIP phones: software and hardware-based. Each come with its benefits and limitations. Below is a comprehensive comparison of the two.

Software-Based SIP Phones

Software-based SIP phones function on computers, smartphones, and tablets, allowing users to make calls from virtually anywhere. They are most popular among remote teams, businesses seeking cost-effective communication solutions, and individuals looking for a more flexible way to stay connected.

These phones boast impressive integration capabilities, streamlining communications within organizations on a more prominent scale. However, their Internet dependence can impact call quality, leading to potential downtime. 

Hardware-Based SIP Phones

Hardware-based SIP phones resemble traditional desk phones with SIP software and network connectivity features. You’ll find them in businesses of all sizes, call centers, and industries where a reliable, dedicated communication device is essential for day-to-day operations and productivity.

Compared to their software-based counterparts, hardware-based SIP phones are more reliable and virtually unimpacted by device performance. However, they may come with higher upfront costs and lack the mobility software-based phones have.

Benefits of SIP Phones

SIP phones, whether software-based or hardware-based, offer numerous benefits that make them a popular choice for modern communication solutions:

  • Cost-effectiveness: SIP phones use VoIP technology, resulting in lower call costs, especially for long-distance and international calls
  • Flexibility and mobility: Software-based SIP phones or softphones enable flexibility for remote work, telecommuting, and communication on the go.
  • Feature-rich functionality: SIP phone features include call forwarding, call waiting, call recording, voicemail, conference calling, and integrations, providing a comprehensive communication solution.
  • HD audio and video quality: With advancements in internet connectivity and codecs, SIP phones can deliver high-definition audio and video calls, ensuring clear and immersive communication experiences.
  • Scalability: SIP phone systems can easily scale to accommodate the growing needs of businesses. Adjusting lines involves straightforward provisioning and configuration, making it simple to expand the communication infrastructure.
  • Global reach: SIP phones aren’t tied to a specific geographic location like traditional phone lines, allowing businesses to establish a virtual presence in different regions.
  • Easy setup and management: SIP phones are generally easy to set up and configure, especially software-based SIP phones. They can be provisioned remotely, saving time and effort for IT administrators.
  • Integration with existing infrastructure: SIP phones work with various IP-based systems, including Private Branch Exchange (PBX) systems, allowing businesses to integrate their communication infrastructure with other business applications and workflows.
  • Reliability and redundancy: SIP phone systems boast redundancy and failover mechanisms to ensure continuous communication even in network disruptions or hardware failures, enhancing overall reliability.

Top SIP Phone Features

SIP phones come with a variety of features that enhance communication and productivity. The top SIP phone features include:

  • Call management: Features like call hold, call transfer, call forwarding, and call waiting enable users to handle incoming and outgoing calls easily and efficiently.
  • HD audio and video: High-definition (HD) audio and video capabilities ensure crystal-clear voice and video communication, improving call quality and a more immersive communication experience.
  • Presence and instant messaging: SIP phones allow users to see the availability status of their contacts and engage in real-time text-based communication.
  • Voicemail and message waiting indication: Voicemail functionality lets users receive and listen to voice messages when they cannot answer calls. Message waiting indication notifies users when new voicemail messages are waiting to be retrieved.
  • Conference calling: SIP phones enable users to participate in multi-party conference calls, making conducting virtual meetings and collaborative discussions easy.
  • Call recording: Some SIP phones allow users to record conversations for later reference, training purposes, or compliance requirements.
  • Do Not Disturb (DND): The DND feature lets users temporarily block incoming calls, ensuring uninterrupted focus during critical tasks or when they are unavailable for calls.
  • Speed dial and contacts directory: SIP phones offer speed dial options and a contacts directory, making it quick and convenient to reach frequently contacted individuals.
  • Caller ID and call history: SIP phones display caller ID information, enabling users to identify incoming callers before answering. Call history logs previous incoming, outgoing, and missed calls for easy reference.
  • Auto-provisioning and remote management: SIP phones with auto-provisioning capabilities simplify the setup process by automatically configuring phone settings. This feature streamlines large-scale deployments and remote management for IT administrators.
  • Headset support and speakerphone: SIP systems include a headset port or Bluetooth support, allowing hands-free communication. Additionally, built-in speakerphones provide convenient hands-free calling during conference or group discussions.
  • Security features: Top SIP phones incorporate encryption protocols and security mechanisms to protect calls and data from unauthorized access.
  • Call queuing and ACD: For call centers and customer support departments, SIP phones can support call queuing and Automatic Call Distribution (ACD) to manage incoming calls and direct them to appropriate agents efficiently.
  • Integration with CRM and productivity tools: Some advanced SIP phones integrate with Customer Relationship Management (CRM) systems and productivity tools, allowing users to access customer information and streamline workflows within the phone interface.

Best SIP Phones Available on the Market 

Below is a comparison of the best available SIP phones on the current market.

FeaturePolycom Trio 8500Polycom Trio 8800Polycom VoxBoxVTech VCS5752Cisco 7841Nextiva X835
LCD DisplayYesYesNoYesYesYes
Speed DialYesYesNoYesYesYes
USB Inputs111001


If you want to take basic phone capabilities to the next level, SIP telephones are the solution you need. Whether software-based softphones or hardware-based devices, SIP phones provide cost-effective and flexible ways to make voice and video calls over the Internet. 

Their feature-rich functionality, including HD audio and video, call management capabilities, and integration with unified communications platforms, ensures seamless and efficient communication experiences. While software-based SIP phones excel in mobility and remote work settings, hardware-based SIP phones offer stability, reliability, and superior call quality. 

With ULTATEL as your service provider, your SIP phone system can be more powerful than ever. We provide solutions for businesses in dozens of niches and pride ourselves on impressive uptime.

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