Skype  

skype.com

RingCentral    

ringcentral.com

Poly          

poly.com

Nextiva    

nextiva.com

Mitel  

mitel.com

Vonage  

8x8  

8x8.com

FreeSWITCH    

freeswitch.org

Lua  

lua.org

Digitcom  

digitcom.ca

Western I.T. Group        

westernit.com

Obihai      

obitalk.com

Quickblox

quickblox.com

XPhone

xphone.com

PanTerra

panterranetworks.com

Optus

optus.com.au

OpenCloud Rhino

opencloud.com

Ooma Telo

ooma.com

OnSIP

onsip.com

Sabsebolo

sabsebolo.com

Nucleus      

nucleus.com

NobelCom

nobelcom.com

3CX

3cx.com

NEC Phones

necam.com

MyOperator

myoperator.co

Mojo Dialer

mojosells.com

Zaplee

zaplee.com

Tadiran

tadirantele.com

Voiceserve

voiceserve.com

VirtualPBX

virtualpbx.com

Vertical

vertical.com

Verified Call

verifiedcall.com

Unilava

unilava.com

Toky

toky.co

Tango

tango.me

TalkRoute

talkroute.com

RCN

ripiocredit.network

Sunwire      

sunwire.ca

SpiderCom

spidercom.net

WebRTC

webrtc.org

Simptel

simptel.com

ShoreTel

shoretel.com

Sangoma

sangoma.com

Voip Unlimited  

voip-unlimited.net

CallRail

callrail.com

Freeje

freeje.com

Five9

Expert Cabling

expertcabling.ca

Easylink Solutions

easylinksolutions.com

Dream Lover

dreamlover.com

Digium

digium.com

Clearwave Communications

clearwave.com

Callture

callture.com

CallTrackingMetrics

calltrackingmetrics.com

G3 Telecom

g3telecom.com

Callfire

callfire.com

Buckeye CableSystem

buckeyecablesystem.com

BrantTel

branttel.com

Better Voice

bettervoice.com

Bandwidth  

bandwidth.com

AVOXI

avoxi.com

Avaya

Analytic Call Tracking

analyticcalltracking.com

Allstream

allstream.com

Inteliquent

inteliquent.com

magicJack

magicjack.com

M2

m2.com.au

Linksys

linksys.com

Line2

line2.com

Jive

jive.com

Jazinga

jazinga.com

Janus Server

janus.conf.meetecho.com

iPlum

iplum.com

Intermedia

intermedia.net

magicJack VocalTec

vocaltec.com

iiNet

iinet.net.au

HotTelecom

hottelecom.biz

GTalk

Grasshopper

grasshopper.com

Gradwell

gradwell.com

Tackle   defunct

gotackle.co

Google Voice

google.com

GetVoIP

getvoip.com