Modifying server settings in VICIdial Admin

Once a server record exists, the Modify Server page is where you actually tune how it dials. There are many fields, but only a handful decide day-to-day behavior. This post covers the ones worth understanding before you put the box into production.

Trunk and call-rate limits

Max Trunks sets the maximum number of lines the auto-dialer will try to use on this server. The default is 96. If you are dedicating fixed capacity, you set it to match — two full PRI T1s, for example, would be 46. This number is the ceiling for everything the dialer places, and any Server trunk reservation you create for a campaign lives underneath it.

Max Calls per Second is the setting people get wrong most often. It caps how many calls the outbound script places each second, from 1 to 100, defaulting to 5. For most SIP (Session Initiation Protocol) carriers you should keep this low — 4 or lower is the safe range, and some carriers cannot handle more than 1 per second. Push the Calls per second (CPS) too high and your carrier starts rejecting calls, which shows up as failed dials rather than a clean error. When in doubt, lower it.

flowchart TD
  A[Auto dialer wants to place calls] --> B{Below max trunks}
  B -- no --> C[Wait for a line to free]
  B -- yes --> D{Below max calls per second}
  D -- no --> E[Throttle this second]
  D -- yes --> F[Place call through carrier]
  E --> F
  C --> B

The active toggles

Two toggles control whether the box does any work. Active Asterisk Server set to N tells VICIdial not to use this box for Asterisk dialing — useful when the machine only runs helper scripts like hopper loading. Active Agent Server set to N stops agents from logging into the agent screen on this server, which matters in a load-balanced phone-login setup. Both default to Y. Getting these backwards is a common reason a freshly added box either does nothing or accepts logins it should not.

Conf-file generation

Generate conf files set to Y lets VICIdial build the Asterisk Conf file entries automatically from your phones, carrier entries, and load-balancing setup. Rebuild conf files forces a fresh rebuild after you change any phone or carrier; once the files are regenerated and Asterisk reloads, the system flips it back to N on its own. Whenever you add or edit a carrier and the change does not seem to take, this toggle is the first thing to check.

Performance logging

System Performance set to Y logs system load, processes, and channel counts. You need this enabled if you want the graphs on the server performance report to populate. One caution worth repeating: logging trades disk space for visibility. On a busy box you may eventually trim it, but leave it on early so you can actually debug problems while you are learning the system.

Two related fields sit next to it and are worth a mention. Server Logs writes the VICIdial scripts' text logs to disk, and AGI Output controls where the dialplan scripts send their debug output. Both default to on, both eat disk on a busy box, and both are tempting to switch off too early. The honest advice is to leave them on while the system is new. When something dials wrong, those logs are the difference between a five-minute fix and a long guessing game.

A quick way to think about the whole Modify Server page: a few fields control how hard the box dials, a few control whether it dials at all, and a few control what gets written to disk. If you read every new field through one of those three lenses, the long form stops being intimidating. Change one thing at a time, rebuild conf files, and watch the result before moving on.

This post is part of our complete guide to installing VICIdial. If you have not created the record yet, start with adding a server in VICIdial Admin.

If tuning trunks, call rates, and conf-file rebuilds by hand is more fiddling than you signed up for, VICIfast delivers a tuned VICIdial server in under 40 seconds with sensible carrier-safe defaults already set.