Outbound call delay on UC300

Hi!
I noticed an unpleasant feature - there is a delay of about 4 seconds between sending the number from the phone and sending the request to the SIP-trunk by UC300. How to eliminate this delay? When there is no delay between calls between internal subscribers, the call passes instantly.
Thanks.

The manufacturer has promised to improve this feature in the next firmware version.

Updated firmware on UC300 from 2.5.6 to 2.5.7. In the description of firmware 2.5.7, the elimination of the delay in an outgoing call was declared.

>> UC-Series-2.5.7-1905-Release
>> Release date: 05/17/2019
>> *Fixed the problem that the incoming and outgoing route recording does not take effect;
>> *Modified the firmware upgrade cache directory;
>> *Optimized call out wait (3 s -> 1 s);
>> *Add fail2ban service switch on the web;
>> *Add a popup reminder on web when upgrading to the 3.x version;
>> *Add upgrade and degrade function between firmware 2.x and 3.x version.
>> Notice:
>> Version 2.5.7 firmware is a transitional version, please upgrade 2.x version to 2.5.7 version before upgrading to 3.x version firmware.

Unfortunately, the delay is still 3 seconds.

hi pavel,

pls use the following lastest 4.1.0 version to test, you need do the factory reset and config manually again after upgrade this version. if still have problem, you can contact me on skype. i will check it remotely.
downloads.openvox.cn/pub/firmwares/IPPBX...ware-iz3-current.bin

skype id： chunlei.yi