Hello,
I have Grandstream HT 503 , and i try to use as a gateway for asterisk .
I could to receive a call from PSTN–> HT 503 --> Asterisk , but i couldn’t to send a call Asterisk -->HT 503 -->PSTN .
I tried many times but 
And this is debug of sip operations in asterisk : fpaste.org/OcJo/
And this is sip.conf , where i define fxo port of HT 503 : fpaste.org/rQBP/
And this is Grandstream HT 503 configurations : postimage.org/gallery/v4rupws/1f427891/
And this is Grandstream HT 503 logs when i send a call from asterisk : fpaste.org/Rk2s/
Hi khaledatteya
I think you should first upgrade the HT-503 to the firmware official versio, then I see that you have HT-503 not registered SIP but on configurations of the asterix this as type=friend
should be “type=peer” on the asterix and clear the pass y user ID.
Review this manual “GXW410x with Ssterix”, the only difference is that is port 5062, which is the FXO port on the HT503
grandstream.com/products/gxw … terisk.pdf
then this, if not work please open a tickets of trouble on tickets system from Grandstream website, here your engineers will help to fix this trouble gladly
please view below the link
grandstream.com/support/submit-a-ticket
Best regards