Kolmisoft Blog

Check your SIP TLS certificate before 2027

Let’s Encrypt removed TLS Client Authentication from its default certificates on 2026-02-11. On 2026-07-08 it retired the temporary tlsclient profile and stopped issuing that...

Mindaugas Kezys
Nov 2, 2026 6 min read

Softswitch migration: match invoices before cutover

Billing breaks a softswitch migration: balances, rate plans, the CDR file, and the first invoice. Bill one month of the old call records on...

Mindaugas Kezys
Oct 26, 2026 6 min read

Answer an ITG traceback from your own CDRs

An ITG traceback response starts in your CDRs. Search Calls List by time, source and destination, name the Origination Point, and stop that trunk.

Mindaugas Kezys
Oct 26, 2026 6 min read

What your softswitch can stop in a SIP DDoS…

You run MOR or M4 yourself. By the end you can tell a full pipe from a SIP flood, set the switch controls that...

Mindaugas Kezys
Oct 26, 2026 9 min read

2026 October: Two critical PHP bugs

On 21 October 2026 the PHP project released fixes for two critical bugs, CVE-2026-109618 and CVE-2026-109619. PHP scored each one CVSS 9.2. On a...

Mindaugas Kezys
Oct 22, 2026 4 min read

High Asterisk CPU: find the cause before a restart

Asterisk at 150% or 250% feels like the server is finished. On a host with several cores, that number can be one or two...

Mindaugas Kezys
Oct 21, 2026 14 min read

Introducing Italian, Ukrainian, and Spanish on Kolmisoft.com

Read Kolmisoft.com in English, Italian, Ukrainian, or Spanish. Choose your language on the homepage, then explore softswitches, pricing, and contact pages the way you...

Mindaugas Kezys
Oct 16, 2026 2 min read

Call-center traffic on a softswitch: what operators need

Office PBX traffic and call-center traffic both travel over SIP. That is where the similarity ends. A predictive dialer can fire more attempts in...

Mindaugas Kezys
Oct 14, 2026 5 min read

When your voice business needs more than 1,000 CPS

A wholesale carrier adds a fast-growing originator. A provider that serves outbound call centres takes on more dialling traffic. Several campaigns hit their busiest...

Mindaugas Kezys
Oct 13, 2026 5 min read

2026 October Development Update MOR sends an onboarding email when a user is created, packs the recordings from a search into one download, and accepts SIP TLS from phones that register through the proxy. Hangup-cause audio can be... Read More

How to send emergency calls from a blocked VoIP account A prepaid balance, a credit limit, and a user marked Blocked exist to stop calls. 999 and 112 are calls, so the same checks stop them. Operators who sell voice to businesses or to... Read More

Forwarded calls fail when the carrier rejects the CLI A forward to a mobile stops, and the handset reports that call forwarding failed. On the outbound INVITE the From number was the original caller. The carrier refused that number. Hosted PBX and white-label... Read More

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