What follows is an incomplete list of leading vendors who are using the main protocols described in one of the previous blog articles: SIP and XMPP. This list is based on my personal knowledge. I apologize in advance for any exclusions.
The goal is to provide material for further analysis by the reader.
Cisco was one of the first to embrace the potential of Unified Communication systems and open standards.
Cisco historically selected MGCP and H.323 as VoIP protocols. SIP was later introduced, first on endpoints and then on servers.
Jabber, Inc., is a provider of presence and messaging software. It’s important to note that Cisco has acquired this company not the open standard Jabber (jabber.org). Jabber, by that point, had already been renamed to XMPP.
Historically, Avaya uses H.323 as the default protocol for VoIP calls. Newer versions support both SIP and H.323 endpoints.
XMPP is the protocol used for chat and presence information.
Both XMPP (presence / chat) and SIP (calls) are supported.
Shoretel bases their presence / chat services on XMPP, while MGCP is the reference protocol for VoIP calls.
IBM Sametime users SIP for both calls and chat / presence services. Federation with XMPP communities and servers is also supported.
WhatsApp uses a slimmed down version of XMPP to work better over mobile devices, which often have limited bandwidth available.
Lync / Skype for Business (Federation)
Microsoft has chosen to use a modified SIP / SIMPLE protocol for their Skype for Business UC platform (formerly known as Lync).
Standard SIP over TCP transport is supported for trunking with other platforms.
In a similar fashion, even if XMPP is not used by the platform itself to handle communications between users, XMPP is supported to federate with remote servers.
Google has started to offer IM and real-time communications integrated into Gmail (for both private and corporate users) via its Google Talk service. The audio and video service is based on Jingle (an XMPP extension). In my opinion, the right choice would have been to use SIP.
The visionary position of Google in bringing even complex applications to the browser has led to the creation of standards like WebRTC.
After creating its social service Google+, Google introduced one of the main features of the social video conferences, branded as Hangouts.
Since 2014, Hangouts have been based on WebRTC.
Hangouts have then taken the place of Google Talk even for one-to-one calls. Hangouts APIs have been deprecated since 2016.
Both SIP and XMPP are supported.
Both SIP and XMPP are supported.
Only SIP is supported.
SIP is the protocol used for call termination. No reference to the usage of XMPP or the availability of advanced chat / presence information was found during the writing of this book.
XMPP is used as a basis for presence, chat services, file sharing, and video sessions. SIP is used for calls, phones based presence, and voicemail notification.
Platforms Support for WebRTC
All of the platforms above can support WebRTC calls via SIP to WebRTC Gateways. However, this is technically not true WebRTC support.
The only systems supporting WebRTC for more than trunking are Innovaphone, Wildix, Mitel, and Switchvox. Therefore, in most cases, WebRTC is still an add-on instead of being a built-in feature.
SIP is the most popular and evolved communication protocol for VoIP and it is still widely supported in the industry. At Wildix, we built our platform on SIP.
XMPP support is not as widespread as it should be. Some vendors are actually reducing Federation support, as much as possible, by using standard protocols.
WebRTC support, as indicated previously, is claimed by most vendors, but, in many cases, it is implemented by simply connecting separate gateways or by using complicated procedures.
My suggestion, if you are looking for a next generation UC platform, is to require support for WebRTC, SIP, and XMPP, and to request a demonstration to see them at work. Systems that do not support WebRTC will become outdated in the next few years, so they should be avoided. Also, you should verify the usability of all the system’s main features.