Are there any Skype restrictions on voice calls on a single IP?

Question

Skype

Recently (during the last 2 months, there was no such thing before) it is impossible to call via skype from the corporate network. The network has a proxy. External IP one.
When you call, there is an attempt to connect, in the Skype window it says Connect and that's it. At the same time, the call does not go through at the other end. It doesn't matter if the callee is on the same network or not. The same thing happens in reverse. It is also impossible to get through from outside the corporate network. This is a normal voice call to one contact without video and conference calls.
At the same time, if I restart skype, the contact I called has a notification of a missed call. And if they called me, then a notification of a missed call appears with me.
In fact, the possibility of voice communication via skype disappeared. Text messages only.
But this does not always happen. Sometimes the call goes through. The other day I was trying to contact a contact outside the corporate network.
I thought that there are some restrictions on communication from one IP. But on the skype website I found only mention of restrictions on group communication - https://www.skype.com/en/legal/fair-usage/
And not a word about the restrictions on regular voice calls. Google didn't answer either.
Are there any restrictions on voice calls? If there are no restrictions, what could be my problems with skype?

Answer 1

No, there are no restrictions.
Problems may be due to the settings of the office gateway.
https://support.skype.com/en/faq/FA148/kakie-porty...