Access to security cameras

[guaranteed]

Hope I am In the right forum area. I have a business with multiple security cameras which I can access from outside world with proprietary software provided me by security camera vendor. I have a static IP address at main system. All router ports have been forwarded that are necessary. The local computer can connect but that is through the local IP, 189.168.x.x. with no problem. I can NOT connect to the cameras from any laptop or desktop that is using the same ISP but security people can connect from there location and I can also connect from most any place outside this main ISP. I have set up monitoring from various location from across country and they work just fine. In other words, all cameras can be monitored from any location except those on this ISP that camera system is on.
I am a bit at a loss for reason why except maybe an ISP problem. The ISP is a line of sight tower high speed system and works just great. Any insight would help me solve this dilemma.

[rthompson80819]

Have you talked to your ISP about this problem?  From what you describe it's got to be something they are doing.  They may not even realize they are doing something to block some access.

[guaranteed]

Not the most responsive ISP. Have several calls in to them. They are closed on weekends. Message service says they will call me, still waiting. Will try again Monday-Thanks.
Just wanted to see if it could be something they could do.
Will come back with results.

[rthompson80819]

I actually added a line or two to my last post about how wireless ISPs usually are lacking in resources, but deleted it at the last minute.

You are just going to need to keep after them to get the problem fixed.  My guess is that they have one guy that really knows what is going on and he is being pulled in six different directions all the time.