Over the years we've had sporadic issues connecting to various sections of the OfficeServ when utilizing port forwarding through the customers firewall. Regular programming would be fine, but anything related to voicemail would come back with some kind of an error. At a point, instead of arguing with the customers IT person...it's just easier to get on their VPN one would think. Often times that works fine too...but we have another problem site.

7400 with 4.98 software. SVMI-20i. All IP's, net masks and gateways are correct. The voicemail works fine. We can access all sections of programming when we are on-site including voicemail. Once we log into the VPN, we start having the same issues when accessing the voicemail sections of programming. We have FTP enabled in the system. The SVMI-20i has been upgraded to the latest software 6.09.

I'm sure there are others out there that have fought this over the years. Wondering if anyone has run across this and what you did to resolve.

What is the error you get?

I am fighting this battle right now as well.
Two sites, one with meraki and the other sonicwall.

I have this problem as well with a 20i. Resetting the 20i will give me remote access for a few days before it goes down again.

I don't mean to hijack this thread but the error I can see with a wireshark trace looks like a block on port 6001 I see the first syn request for the TCP connection then a couple re-transmits but then no syn,ack response.

Recently the IT folks I'm working with identified the attempted connection as an active FTP one that is not supported by some recent firmware(Meraki specifically but possibly Sonicwall too).

They are going to try a patch to see if that sorts it.

I'll let you know how that goes.

-W

Further investigations confirms definitely NOT active FTP.

Support for Passive FTP was added in 4.8 or 4.9 software.
I've found it seems very dependant on the router.

Also sometimes forwarding TCP port 20 helps.

On one system I had trouble with, the client put OSDM on a virtual server, I remote desktop to that server and so far so good.