Asterisk Registration

Hello everybody I resolved the problem with asterisk making outgoing calls but now, i can not receive calls from PSTN, asterisk show me a NOTICE, and i think that is the port 5061 that is not opened, because if i change that entension to the 5060 por works perfectly.

in the spa3102 config i have the line 1 in port 5060
and the pstn line in the port 5061.

pstn line = spa400

bit i dont know how open ports in Debian can anyone help me please

here is the messages that asterisk show

[Jan 30 16:16:41] NOTICE[2981] chan_sip.c:7422 sip_reg_timeout – Registration for spa400@ip de asterisk timed out, trying again (Attempt #1)

if anybody can help me please

Thank you