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Configuration guides, comparisons and plain answers on SIP trunking, Asterisk, FreePBX, softphones, numbers and porting. 52 articles, written by the people who run the network. RSS.
Latest
- Asterisk Ports Explained: SIP 5060, RTP 10000-20000 & FirewallGuide · Oct 15, 2026Every port Asterisk needs: SIP 5060/5061, RTP 10000-20000, plus iptables, UFW and cloud security-group rules, NAT settings and Fail2Ban for SIP trunks.
- Best SIP Softphone for Windows 2026: Bria vs Zoiper vs MicroSIPTools · Oct 15, 2026We tested the best Windows SIP softphones: MicroSIP, Linphone, Zoiper and Bria. Compare codecs, cost and features, plus step-by-step setup.
- 10 Best SIP Softphones (2026): Free for Windows, Mac & MobileSoftphones · Oct 15, 2026What a SIP softphone is and the 10 best to download in 2026: Zoiper, Linphone, MicroSIP, Groundwire and more. Free for Windows, Mac, iOS and Android.
- One-Way Audio Fix for VoIP & Asterisk: NAT, SIP ALG, RTP PortsTroubleshooting · Oct 15, 2026Fix one-way audio on VoIP calls: NAT, blocked RTP ports 10000-20000 and SIP ALG. Step-by-step fixes for Asterisk, FreePBX, routers and SIP softphones.
- 800 Vanity Numbers: How to Get a Custom Toll-Free Number (2026)Product · Oct 15, 2026How to get an 800 vanity number: search available 800, 888, 877, 866 and 855 toll-free numbers, pricing from $2/mo, setup and porting.
Industry News
- Lumen Exiting Voice: SIP Trunking Alternatives & Migration GuideSep 5, 2026 · 9 min readLumen stopped selling SIP trunking and Voice Complete on Aug 1, 2026. What changes at contract end, how to port numbers.
Getting started
- SIP Trunk Testing: How to Test a Trunk Before You Pay (2026)Sep 5, 2026 · 10 min readTest a SIP trunk before you commit: no trunk fees, $0 per channel, no card required. Verify audio, DTMF and codecs, then pay $0.009/min.
- Microsoft Teams Direct Routing Setup Guide 2026 | SIP TrunkingMar 27, 2026 · 15 min readComplete guide to Microsoft Teams Direct Routing with IPComms SIP trunking. Setup steps, SBC configuration, pricing comparison vs Microsoft Calling Plans.
- What is SIP Trunking? The Complete Guide for 2026Mar 27, 2026 · 15 min readLearn what SIP trunking is, how it works, and why businesses are replacing traditional phone lines with SIP trunks.
Asterisk
- Asterisk Ports Explained: SIP 5060, RTP 10000-20000 & FirewallOct 15, 2026 · 18 min readEvery port Asterisk needs: SIP 5060/5061, RTP 10000-20000, plus iptables, UFW and cloud security-group rules, NAT settings and Fail2Ban for SIP trunks.
- Asterisk PJSIP Tutorial: Endpoints, Transports & pjsip ReloadOct 1, 2026 · 18 min readAsterisk PJSIP tutorial: endpoints, AOR, transports, pjsip reload vs core restart, WebRTC/DTLS, chan_sip migration. Working pjsip.conf for Asterisk 18-23.
- Asterisk PJSIP Trunk Setup: pjsip.conf, NAT & IP Auth GuideSep 15, 2026 · 12 min readAsterisk SIP trunk configuration with PJSIP: pjsip.conf endpoint, AOR and identify sections, NAT (external_media_address, local_net), IP auth, test calls.
- Asterisk Queues.conf Guide: Setup, Strategies & AnnouncementsAug 1, 2026 · 10 min readComplete Asterisk queues.conf guide — ring strategies, periodic announcements, hold-time updates, and queue member config with working examples for 2026.
- Asterisk Dialplan Tutorial: extensions.conf & Pattern MatchingJul 15, 2026 · 25 min readAsterisk dialplan tutorial: extensions.conf syntax, pattern matching, variables, functions, and call routing examples for SIP trunks.
- How to Build an IVR Auto Attendant in AsteriskJan 21, 2026 · 18 min readComplete guide to asterisk IVR setup including auto attendant configuration, menu systems, business hours routing, and SIP trunk integration.
- Asterisk Voicemail Setup: Complete Configuration GuideJan 19, 2026 · 14 min readComplete guide to Asterisk voicemail configuration with SIP trunking. Set up voicemail to email, MWI, custom greetings.
- Asterisk Security Hardening: Protect Your PBX from AttacksDec 20, 2025 · 14 min readEssential security hardening for Asterisk PBX systems. Prevent toll fraud, brute force attacks, and unauthorized access with these proven configuration.
- What is Asterisk PBX? Complete Guide to Open Source VoIPDec 5, 2025Learn what Asterisk PBX is and how it works. Complete guide to open source VoIP, FreePBX comparison, features, hardware requirements, and getting started.
- Getting Local Phone Numbers for Your Asterisk PBXNov 18, 2025 · 12 min readHow to get local phone numbers (DIDs) for your Asterisk PBX. Choose area codes, configure inbound routing, and set up multiple numbers on a single SIP.
- Best SIP Trunk Provider for Asterisk & FreePBX 2026 | Free TrunksOct 28, 2025 · 15 min readCompare top SIP trunk providers for Asterisk and FreePBX in 2026: per-minute rates, channel fees, PJSIP support and how to trial each one.
- How to Set Up Voicemail on Asterisk PBXJun 22, 2025 · 8 min readComplete guide to setting up voicemail on Asterisk PBX. Configure voicemail.conf, enable email notifications, set up visual voicemail.
- Install Asterisk on Debian 13 (Trixie) — 2026 GuideMar 12, 2025 · 15 min readStep-by-step Asterisk install on Debian 13 Trixie — dependencies, compilation, systemd & PJSIP config. Free SIP trunks from IPComms, only pay for usage.
FreePBX, 3CX and FusionPBX
- Install FreePBX 17 on Debian 12: Official Script Guide 2026Sep 17, 2026 · 20 min readInstall FreePBX 17 on Debian 12 using the official sng_freepbx_debian_install script. Complete setup from dependencies to SIP trunk config.
- FreePBX SIP Trunk Setup: PJSIP Trunk, Inbound & Outbound RoutesSep 15, 2026 · 11 min readFreePBX SIP trunk configuration step by step: PJSIP trunk settings, IP authentication, inbound and outbound routes, test calls. $0 per channel, $0.009/min.
- FreePBX Outbound Routes & Dial Patterns: Setup Guide 2026Jul 15, 2026 · 18 min readConfigure FreePBX outbound routes and dial patterns for SIP trunking: US, international, and 911 emergency call routing with working examples.
- FreePBX Troubleshooting: Registration Failures & One-Way AudioFeb 11, 2026 · 15 min readFix FreePBX registration failures and one-way audio — step-by-step NAT, firewall, SIP & RTP solutions. Free SIP trunks from IPComms, only pay for usage.
- How to Set Up a SIP Trunk in 3CX with IPCommsJan 12, 2026 · 14 min readStep-by-step guide to configuring a SIP trunk in 3CX. Set up IP authentication, outbound rules, inbound routing.
- FusionPBX SIP Trunk Setup Guide | Configure with FreeSWITCHOct 14, 2025Complete FusionPBX SIP trunk configuration guide. Connect IPComms to FreeSWITCH-based FusionPBX with step-by-step gateway, dialplan, and route setup.
- 3CX SIP Trunk Configuration with IPCommsOct 3, 2025 · 8 min readStep-by-step guide to configuring a SIP trunk in 3CX Phone System with IPComms. Set up inbound/outbound routes, codec settings, and test your connection.
Softphones
- Best SIP Softphone for Windows 2026: Bria vs Zoiper vs MicroSIPOct 15, 2026 · 12 min readWe tested the best Windows SIP softphones: MicroSIP, Linphone, Zoiper and Bria. Compare codecs, cost and features, plus step-by-step setup.
- 10 Best SIP Softphones (2026): Free for Windows, Mac & MobileOct 15, 2026 · 14 min readWhat a SIP softphone is and the 10 best to download in 2026: Zoiper, Linphone, MicroSIP, Groundwire and more. Free for Windows, Mac, iOS and Android.
- Best SIP Softphone Apps for Android 2026: Tested & ComparedSep 5, 2026 · 11 min readThe best Android SIP apps compared: push notifications, battery drain, codecs and TLS. Includes step-by-step trunk setup for each app.
- Sipnetic Softphone for Android: SIP Setup, Push & TLS 2026Jul 15, 2026 · 10 min readSipnetic Softphone for Android: SIP account config, push notifications, TLS/SRTP encryption, codecs, and battery tuning. Free Groundwire alternative.
- Free SIP Softphones for Asterisk, FreePBX & LinuxJan 3, 2026 · 9 min readFree SIP client apps tested with Asterisk and FreePBX. Linphone, MicroSIP, and Zoiper compared with config examples for Linux, Windows.
- VoIP Phone Buying Guide 2026: Best IP Phones for BusinessNov 22, 2025Complete VoIP phone buying guide. Compare Yealink, Polycom, Cisco and Grandstream desk phones by features, price and SIP compatibility.
- Zoiper Softphone Setup Guide: Configure with IPComms SIP TrunkJun 15, 2025 · 12 min readComplete Zoiper setup guide for IPComms SIP trunks. Step-by-step configuration for Windows, Mac, Linux, iOS and Android.
Numbers, toll-free and porting
- 800 Vanity Numbers: How to Get a Custom Toll-Free Number (2026)Oct 15, 2026How to get an 800 vanity number: search available 800, 888, 877, 866 and 855 toll-free numbers, pricing from $2/mo, setup and porting.
- Free DID Numbers vs $1.50 SIP Numbers (2026)Sep 16, 2026 · 10 min readIPComms no longer offers free DID numbers. See what Google Voice, TextNow and TextFree really give you, and what a SIP-ready number for $1.50/month adds.
- Bulk Number Porting: 100+ Numbers with Volume DiscountsSep 7, 2026 · 6 min readMoving 100+ phone numbers to IPComms: volume discounts on the $5 per-number port fee, one project owner, parallel port orders and a zero-downtime cutover.
- Toll-Free SIP Trunking: 800 Number Setup, Porting & PricingJul 15, 2026 · 10 min readToll-free SIP trunking guide: how 800/888 numbers work over SIP, origination vs termination, vanity setup, porting, and per-minute pricing.
- Toll-Free Number Porting Guide: 800, 888, 877 NumbersNov 27, 2025 · 11 min readComplete guide to porting toll-free numbers (800, 888, 877, 866, 855, 844) to a SIP trunk. RespOrg transfers, timelines.
- How to Port Your Phone Number to a SIP TrunkNov 5, 2025 · 10 min readStep-by-step guide to porting your existing phone number to a SIP trunk provider. Learn about LOAs, porting timelines, and how to avoid common mistakes.
Security and compliance
- SIP TLS & SRTP Guide: Port 5061, Encrypted SIP Trunks & AsteriskSep 15, 2026 · 18 min readSIP TLS on port 5061 and SRTP encrypt VoIP calls. Encrypted SIP trunk setup, Asterisk PJSIP transport and media_encryption config, HIPAA notes, testing.
- Can You Call 911 From VoIP? E911 Rules, Setup & Testing (2026)Sep 5, 2026 · 12 min readVoIP can call 911 only when E911 is configured. How VoIP 911 works, Kari's Law and RAY BAUM's Act rules, Asterisk/FreePBX/3CX setup, and how to test it.
- PBX Hacking Explained: 11 Ways to Detect & Prevent Toll FraudJul 7, 2026 · 20 min readPBX hacking explained: how attackers break in, profit from toll fraud, and 11 proven ways to detect, block, and secure Asterisk.
- SIP Trunk Security Best Practices for Enterprise VoIPAug 14, 2025 · 10 min readLearn essential SIP trunk security best practices including encryption, access control, monitoring, and fraud prevention to protect your enterprise VoIP.
Reliability, capacity and troubleshooting
- One-Way Audio Fix for VoIP & Asterisk: NAT, SIP ALG, RTP PortsOct 15, 2026 · 12 min readFix one-way audio on VoIP calls: NAT, blocked RTP ports 10000-20000 and SIP ALG. Step-by-step fixes for Asterisk, FreePBX, routers and SIP softphones.
- How Many SIP Trunks Do I Need? Capacity Calculator (2026)Aug 1, 2026 · 14 min readHow many SIP trunks do you need? Concurrent-call sizing with Erlang B tables, bandwidth math, and $0 channel-limit pricing from IPComms.
- SIP Trunk Failover & Redundancy: DNS SRV, Multi-Provider GuideAug 1, 2026 · 14 min readBuild SIP trunk failover and redundancy: DNS SRV, multi-provider routing, Asterisk redundancy, geo-redundant PoPs, and disaster recovery patterns.
- VoIP Network Requirements: Bandwidth, QoS, and InfrastructureSep 28, 2025 · 10 min readLearn the network requirements for quality VoIP calls. Covers bandwidth calculations, QoS configuration, jitter and latency targets.
- Unlimited SIP Trunking: Is It Worth It? Metered vs UnlimitedAug 28, 2025 · 10 min readCompare unlimited vs metered SIP trunking plans. Learn about hidden costs, fair use policies, and when each pricing model makes sense for your business.
Pricing and comparisons
- Best SIP Trunk Providers 2026: 10 Compared on Price & SupportSep 5, 2026 · 13 min read10 best SIP trunk providers for US businesses in 2026: per-minute rates, channel fees, contracts, support and PBX fit compared, with picks by use case.
- How Much Does SIP Trunking Cost? Pricing Models & Fees (2026)Sep 5, 2026 · 12 min readWhat SIP trunking really costs in 2026: per-channel vs per-minute models, typical rates, hidden fees, and real monthly bills for a 10-line office.
- SIP Trunking vs PRI: Complete Comparison Guide for 2026Mar 27, 2026 · 10 min readSIP trunking vs PRI comparison. See why businesses are replacing PRI lines with SIP trunks — 40-60% cost savings, instant scalability.
- SIP Trunking Benefits: 10 Reasons to Switch from PRI/POTSJan 21, 2026Discover the top benefits of SIP trunking over PRI and POTS. Cost savings, scalability, HD voice, disaster recovery, and more. Complete comparison guide.
Business and call centers
- Call Center SIP Trunking: $0 Channel Fees, No Set Call LimitsSep 15, 2026 · 15 min readSIP trunking for call centers and contact centers: $0 per channel, no set concurrent-call limits, $0.009/min inbound, STIR/SHAKEN, PRI cost comparison.
- SIP Trunking for Small Business: Benefits and Cost SavingsJul 11, 2025 · 8 min readLearn why small businesses are switching to SIP trunking. Compare costs with traditional phone lines, explore features.