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spa3102 (FW: 5.1.10GW) keeps loosing registration on PSTN line only

SPA3102 with firmware version 5.1.10GW (hardware version 1.4.5a) that keeps on loosin gthe registration of the PSTN Line only when connected remotely (outside of the local network where the PBX is located).  My SIP server is based on PBX in a Flash, and it is working with all latest patches based on Asterisk 1.4.

LINE1 of SPA3102 registers properly and stays registered without a problem (port number assigned to this line is 5060), but PSTN Line tries to registeres, if it succeds, it will loose its registation within 10 seconds (port number assigned to this line is 5061).  All ports neccesary and NAT configuration on my firewall are correct, if not, LINE1 will not register either.

If I place the SPA3102 on the local network, then the problem dissapears and both Line1 and PSTN Line stay registered without a problem.  I cannot understand how just by changing the PROXY address with my FQDN or static public IP address causes only the PSTN Line to loose registration.  Any suggestion on how to troubleshoot this problem will be greatly appreciated.  If need be, I can provide the configuration for the VOICE portion of the SPA3102 as an HTML file.


On further troubleshooting, I downgraded the unit to firmware version to 5.1.7GW, as I read that there are some possible issues with firmware version 5.1.10GW, but the problem is still the same.  The SPA3102 registers properly when inside the local network and the proxy is set to 192.168.1.XXX, but when the proxy gets replaced by the FQDN of the PBX in a Flash server (all other configuration parameters remain unchanged), and I place teh SPA3102 on a different network, then LINE1 registers properly, but PSTN Line does not register.  It seems as if the PSTN Line proxy parameter is not being recognized properly whether it is the FQDN or the actual static IP address of the PBX.



Message was edited by: markiper_cisco

Cisco Employee

Re: spa3102 (FW: 5.1.10GW) keeps loosing registration on PSTN li

Dear Sir;

This is likely a network/config issue. Could you please send us the debug or network traces that shows the SIP signaling exchange between SPA3102 and the proxy?


New Member

Re: spa3102 (FW: 5.1.10GW) keeps loosing registration on PSTN li

Hello Laberto,

Thanks for your reply.  I found out what seem to be the issue, and it was in fact a configuration issue.  There is some contradiciting information on different manuals and configuration guides posted online in different repositories from SIPURA, LINKSYS and now CISCO.

First of all, when working with asterisk and using SIP_NAT.CONF to define your FQDN or public IP address and LAN IP for the asterisk server, there is no need to enable either NAT MAPPING or NAT KEEP ALIVE features on the SPA3102 that is connecting back to the asterisk server remotely.  If those features are enable, the SPA3102 will try to register in very odd ports, even though UDP ports on the 5060 range have been configured on the unit.  This will cause the SPA3102 to register for a couple of seconds, and loose it registration altogether.

Second of all, when crafting the dial plan to use for the PSTN-to-VoIP Gateway section of the SPA3102, dial plan that will allow asterisk to do all call routing, there is informtion online that mention the need for the port number after the FQDN or IP address of the asterisk server, so I was using a dial plan such as the following:


I found out (the hard way) that including the value of the port number on the dial plan above only causes the SPA3102 to register for a few seconds, and then loose its registration automatically, so the correct way to craft the dial plan is as follows, independently of the port number you are using for SIP messaging:


After making those changes, everything seems to be working correctly on the SPA3102, but I am only testing FW 5.1.7GW as the latest 5.1.10GW seems to still cause some issues even after those changes.  One last questions, is there a link that you can provide with the oficial administration guide for the SPA3102 from CISCO?  At least having the latest official administration guide from Cisco will help me when trying to troubleshoot issues as the one I just encounter after 5 years of working with SPA units, even back from when they were SIPURA.



Cisco Employee

Re: spa3102 (FW: 5.1.10GW) keeps loosing registration on PSTN li

Hi Marco,

Thanks for sharing your experiences and insights.

The ATA documentation is located at:

The specific SPA ATA Admin Guide [SPA2102, SPA3102, SPA8000, SPA8800, & PAP2T] that you asked for is at:




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