Agent4 vs. SIPSTACK Comparison Chart

Zoom Phone is an AI-powered cloud-based business phone system that provides voice calling, messaging, and unified communications through a Voice over Internet Protocol (VoIP) platform. The software enables employees to make and receive business calls from desktop computers, mobile devices, and compatible desk phones. Its calling features include auto receptionists, call queues, call forwarding, voicemail, call recording, SMS, and intelligent call routing. Built-in AI capabilities provide post-call summaries, voicemail transcription, action item extraction, and automated follow-up assistance. Zoom Phone also supports an optional AI receptionist that answers customer inquiries, schedules appointments, and transfers calls to appropriate employees. The platform integrates with Zoom Meetings, Zoom Chat, Salesforce, Microsoft, Google, and other business applications while providing centralized administration and call analytics.

Calling made modern. Your business number. Your employees' phones. Our amazing features. A dial menu spoken by our voice actors. Callers press numbers to make purchases, hear MP3s, connect to specific staff, and more. Make and answer calls using your number on multiple phones without the caller ever knowing. Employees hear secret in-house menus, transfer calls, and send voicemails to their email, all from their dialpad. These business features require no new software or hardware. Your dialpad come to life. Porting your business or personal number at the press of a button. Select from our menu of modern voice features for your business or personal line. We'll activate these features on your current phone for you. No work (or learning) required from you. We'll be here to transform your number whenever your desires change.

Our autodialer software are used for automating sales calls, payment collections, appointment reminders, phone polling and market research. It can also be used for mass emergency voice broadcasting. The system is ideal for Telcos and companies selling callcenter services as it is multi-tenant with billing and white-labeled while being economical to run as you choose your own Voice Provider. Our autodialer software can massively increase productivity by dropping busy, unanswered and disconnected line, passing calls answered by real people back to your agents, and leaving messages on answering machines.

Activate your new international phone number in 60 seconds. Choose from phone numbers in over 120+ countries and 1,000 cities. Forward your calls to any phone number in the world. Robust scheduling options allow you to route your calls based on the days and hours of your business. Route your calls to your main call center during business hours and to voicemail during non-business hours. Instantly view detailed information about calls made to your TollFreeForwarding phone number. Learn about your customers' call habits to help make decisions about outbound sales and follow-up. Keep track of your calls by recording all or some of your calls. Recorded calls are stored in call detail records and can be played or downloaded at any time.

CTM, formerly known as CallTrackingMetrics, is a conversation intelligence and call tracking platform that helps businesses measure marketing performance, manage customer communications, and improve sales conversions. The software tracks phone calls, text messages, website forms, and chats to identify the advertising campaigns and channels that generate customer inquiries. Its AI-powered conversation analytics provide call transcription, summarization, sentiment analysis, and lead scoring. CTM also offers intelligent call routing, automated follow-ups, AI voice agents, and contact center management tools. Reporting dashboards help organizations analyze marketing attribution, advertising return on investment, customer interactions, and sales team performance. The platform integrates with Google Ads, Google Analytics, HubSpot, Salesforce, and other business applications to connect marketing data with customer conversations and revenue outcomes.

800.com is a business phone and call tracking platform that helps small and growing businesses understand, manage, and respond to inbound calls more effectively. The platform provides local and toll-free numbers, call tracking, call recording, voicemail, SMS, and detailed call reporting so teams can see where calls come from and how they’re handled. Businesses use 800.com to track phone leads across websites, ads, social media, and offline marketing, improve response times, and follow up on missed calls. With integrations for Google Ads, GA4, Meta, Microsoft Ads, and popular CRMs, 800.com connects call data to marketing and sales workflows. The platform is easy to set up, flexible as businesses grow, and designed to turn phone calls into clearer insights and better customer experiences.

Bigly Sales is a fully managed AI calling platform for sales teams, lead generation companies and call centers. AI voice agents call, qualify, nurture and live-transfer leads around the clock, answer inbound calls, and book appointments, while every outcome writes back to your CRM. You don't assemble the stack yourself. Bigly writes your call scripts with Claude, ChatGPT and other leading LLMs, then tests script versions against each other on live traffic and keeps the one that converts best. Phone numbers, carrier registration, more than 200 whitelisted lines with local presence, spam monitoring, call routing and campaign setup are handled for you before the first dial. Each call is checked against consent, suppression lists, known TCPA litigants and state and federal calling rules, including quiet hours, before it is placed. Reporting is built around the result you pay for. The dashboard tracks success rate per lead, cost per transfer and cost per human contact, plus a dial-to-transfer funnel that shows where calls drop off: no answer, DNC request, failed qualification, or a transfer the agent never picked up. Leads can arrive in real time from API vendors or as uploaded lists, and every source is ranked by success rate and cost, so you can see which lead vendors pay off. An hour-by-hour view shows when your leads actually convert. The Bigly Sales MCP server lets you run the account by asking Claude or ChatGPT: add leads to an active campaign, check pacing and minute usage, pull call summaries and transcripts, or find out who picked up today and wants a demo. Common uses include aged and dead lead reactivation, speed-to-lead follow-up on web and vendor leads, appointment setting, inbound answering and overflow, and warm transfers to licensed agents in insurance, lending, home services, legal, auto and political fundraising. Integrations include HubSpot, Salesforce, Zoho CRM, Pipedrive, GoHighLevel, Close, Follow Up Boss, Keap, monday CRM, Freshsales, ActiveCampaign and Microsoft Dynamics 365, plus an API for real-time lead posting. Plans start at $99 a month for 500 minutes, and Hunter, Closer and Rainmaker add a dedicated account manager who watches results and tunes your campaigns. New customers start with a free 30-minute AI calling setup ($3,000 value): the team builds your calling system live, shows the MCP and runs a test call.

net2phone is an AI-powered business communication platform for companies serious about customer experience. Trusted by 500,000+ users and backed by 30+ years of experience, net2phone eliminates the friction of scattered channels and disconnected tools, so every conversation drives retention and growth. Unite unifies voice, messaging, video, and chat in one place, with call recording, sentiment analysis, and AI-generated follow-ups. AI Agent automates customer inquiries and workflows across phone and chat in 30+ languages, handing off to humans when needed. Coach AI reviews 100% of interactions to guide agent performance. uContact gives high-volume teams omnichannel routing and real-time dashboards. Every solution integrates with the tools you already use and runs on enterprise-grade security. Beyond software, net2phone provides expert guidance at every step, from setup to integration to ongoing optimization, so your technology delivers measurable results.

iPlum is a mobile first solution for business professionals. iPlum works on your existing smartphone without changing carriers. Get best call quality & text in any situation. Give a professional touch for your business with phone tree virtual extensions. Works well for both large businesses and solo professionals. Promptly respond to your calls & texts during business hours and send them directly to your voicemail during non-business hours. Organize your team with a centralized portal. Add and manage iPlum users with different profiles and permissions in a corporate account. Tell your customers you care by automatically sending smart business text for missed calls or texts. Attach a signature for your texts. Texting in legal or healthcare business requiring HIPAA compliance, use secure channels with encryption. Your clients get FREE iPlum app to send you secure texts. It is critical to protect client data as per privacy and security regulations.

QEval is contact center quality assurance software that automates quality monitoring across 100% of voice, chat, and email interactions. Most call center QA teams manually sample 1 to 5% of calls. QEval replaces that with AI-powered speech analytics, automated quality scoring, and real-time compliance monitoring. Core functionality: call monitoring and evaluation, agent performance management, sentiment analysis, keyword detection, customer experience analytics, coaching workflows, gamification, and 110+ dashboards with predictive analytics. Compliance monitoring covers PCI, HIPAA, and GDPR with 98% accuracy and real-time alerts. QEval's speech analytics engine is trained on 138M+ interactions with 94% classification accuracy. The platform deploys in 30 days, not the 90 to 120 days typical of call center quality monitoring software. ISO 27001, SOC 2, PCI-DSS certified. Built by Etech Global Services for Fortune 500 contact centers in healthcare, telecom, retail, banking, and BPO.