For the record, I have tested a Sipgate account in Voxalot and it does register.
The settings I am using are the following :
Provider Name : Sipgate (Any choice)
User Name : Account No (7 digits, not the PSTN DID number)
Codecs : Leave default or your preference (Eg. ulaw;alaw;g729;gsm)
Host : sipgate.co.uk
Port : 5060
Active ; Yes
SIP register : Yes
Optimize Audio Path : No
Sipgate does not allow calls from other VoIP networks by peering through SIPBroker. You can see that Provider Number *211 has a Red X mark against it, on the following page:
SIPBroker - Provider White Pages
However, you can call the Sipgate account registered in Voxalot in the Voice Service Provider list from another Sipgate account.
I have not tested a DID number with this Sipgate account.
Regards