The RTCP extended report VoIP metrics block specified by RFC 3611 is generated by an IP phone or gateway during a live call and contains information on packet loss rate, packet discard rate (because of jitter), packet loss/discard burst metrics (burst length/density, gap length/density), network delay, end system delay, signal/noise/echo level, mean opinion scores (MOS) and R factors and configuration information related to the jitter buffer. VoIP metrics reports are exchanged between IP endpoints on an occasional basis during a call, and an end of call message sent via SIP RTCP summary report or one of the other signaling protocol extensions. VoIP metrics reports are intended to support real-time feedback related to QoS problems, the exchange of information between the endpoints for improved call quality calculation and a variety of other applications.
also enables T56A  to work as a base station which can be registered with up to 4 compatible Yealink handsets. This solution provides you with a quick and reliable DECT connection without wiring or cabling. As a complement for Yealink DECT series, attaching DD10K to your desk phone offers you a new solution by combining the desk phone’s features with DECT capabilities.
Yealink YHS33-USB is a professional headset with the over-the-head style that eliminates background noise and helps you get in your concentration zone and focus. Coupled with wideband audio technology and HD voice, the YHS33-USB delivers richer and clearer conversations, as well as reduces listening fatigue. Simple plug-and-play setup allows you to use the USB port to the USB-supported Yealink IP phones, plug it into the USB port or 3.5mm jack to your laptop, or use the 3.5mm jack straight into your smart device. Get easy access at your fingertips via the intuitive control unit to the frequently-used functions, such as accept incoming calls, adjust volume and mute the microphone. Yealink YHS33-USB stands its unique position in the market with the combination of exceptional comfort, durable lifecycle, premium quality, and brilliant sound.
Few things in life are set in stone, and the same should be true of your VoIP plan. It’s wise to find a plan that is scalable and which you can easily expand if need be. You’ll want to know if you can break your contract early if you find a better deal elsewhere, or if you can easily switch plans with the same company in order to take advantage of more features, or to get rid of some you don’t need. 
Softphones are increasing in importance in VoIP offerings to the point that for some they're the only choice. They are a critical part of UCaaS and are as common on mobile phones and tablets as they are on desktop PCs. For workers in call centers, softphones are a common tool because of they're the front-end window of any CRM or help desk integration. So, for example, a softphone can combine a telephone conversation with text chat and screen sharing, which means a conversation between two employees can seamlessly add more participants, handle private text chats between those participants while the call is still going on, and extend to a collaboration session in which the group shares screens, documents, and data—no prep, no reserved lines, just button clicks.  
E.164 is a global FGFnumbering standard for both the PSTN and PLMN. Most VoIP implementations support E.164 to allow calls to be routed to and from VoIP subscribers and the PSTN/PLMN.[27] VoIP implementations can also allow other identification techniques to be used. For example, Skype allows subscribers to choose "Skype names"[28] (usernames) whereas SIP implementations can use URIs[29] similar to email addresses. Often VoIP implementations employ methods of translating non-E.164 identifiers to E.164 numbers and vice versa, such as the Skype-In service provided by Skype[30] and the ENUM service in IMS and SIP.[31]
The only additional piece of equipment that you need is an Analog Telephone Adapter (also referred to as an ATA) that allows you to connect your existing telephone to your home Internet. This equipment is typically provided on a free lease basis from the home VoIP provider that you choose, or you can use you own device if you prefer. You can also use IP phone(s) instead of using the ATA with your existing analog phones. The sound quality is better but there is more up front cost as IP phones are more expensive than the ATA devices.