Hey all. Trying to setup a Grandstream GP750 with my voip.ms service. It registers fine as seen both on the device itself and on my voip.ms account. I can receive calls fine, but I am unable to dial out. I get a 503 error on the phone as soon as it tries to dial a number. I’ve followed the wiki instuctions for the GP750, but even with that I can’t dial out. I’m sure it’s something dumb, but I can’t see what it could be. Any pointers?
Hello @ChinookTX,
Are you using SIP TLS? If no, do yourself a favour 
. If yes, are you sure you did setup the SRTP setting correctly (and “Force” it)?
I had to setup a DP750 a few weeks ago and I had to really dig in the menus here and there to get everything right. But I have no device in hand (nor a good memory) to help out.
I can only confirm that it works (I was using TLS/TCP) but I have to find the right option (especially the SRTP one I believe).
Kind regards!
Thank you for your response. I am using SIP TLS yes, and I configured my subaccount to encrypt calls, as well as my base station with TLS encryption. I got fedup this morning and deleted the sub-account and created a new one. It worked first time… There must have been something I changed way back that didn’t play nice with the DP750.
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Yes, it was not the easiest device to configure, but it finally worked. I am glad you could figure it out, somehow.
Kind regards.
As a side not on DP750, I would recommend not using the ‘parallel’ mode if you got several handset, I ran into some sneaky issues.
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I’m curious what problems you’ve encountered with parallel mode. It has been working fine for me for a few years.
Call transfer would randomly failed to connect. This was confirmed by support that parallel mode could cause such issue.
Ah! We have a small house, I usually just walk the phone over to the person being called. 