Yes, the SIP client works 'exactly' the same way than the Gizmo client in voice calls.

If it is so, what client will pick up the phone on incoming calls? SHould I uninstall Gizmo in order to use SIP client?

You don't have to uninstall it but just make sure it is not running at the same time... If you find the built in SIP client does everything you need, then you can uninstall the Gizmo client.

Just tried it with SIP client - same result. Tried to switch port 5060 to another one, but could not connect at all. Well, I gave up. Will leave it to the future.

Good thread you have going here.

I have extensive experience using GizmoProject with devices (including N800), and several home routers.

First I have to tell you that even with the N800 IP address DMZ'd I have trouble with SIPPHONE regardless of whether I used the N800 built-in client ( RTCOMM ) or the Gizmo Client. This problem extends to desktop computers trying to do SIP thru certain routers.

It can get complicated...... one of my routers is the popular Linksys WRT54G (version 5). This Linksys router uses synchronous NAT, and I read somewhere that this doesn't work well with STUN. I also know that GIZMO does NOT work with outbound proxy. Outbound proxy is what you'd use if your router has synchronous NAT. Outgoing proxy is an alternative to STUN. Sooooo, my WRT54G didn't operate as it should with STUN ( synch. NAT issue ) and Gizmo Project doesn't allow any outbound proxy. What to do??

I also have a "device" known as a Sunrocket 6011S. I spent many hours struggling with this trying to get it ( and / or the N800 ) to work nice with SIPPHONE ( GIZMO ). I learned that if I placed the Sunrocket 6011S on the public side of my Linksys WRT54G all worked as expected. There was a problem with Bittorrent going thru the 6011S but explaining that will get me way off track here. I also spent much time with the AC211, it is another Sunrocket device.... an ATA with RJ11's. Anything on the private side of my WRT54G was a problem ( N800, Gizmo desktops, 6011S, AC211). I also spent quite a bit of time with SJ_Labs SIP soft client configured for Gizmo on the private side of my router.

My neighbor allowed me to use HIS wireless network. He has a similar (but not identical) Linksys home router. He has the WRT54GS (speedboost). What I learned from this test is that his WRT54GS was "friendlier" to my SIP "devices" than my WRT54G. I could do all kinds of things on the private side of HIS network and SIPPHONE worked well. I did a USB wifi link to a laptop (my neighbors network), then bridged (XP) that to the Ethernet port on the laptop and connected the Sunrocket AC211 and the Sunrocket 6011S with success.

Everything was pointing to my Linksys WRT54G as the common denominator causing the problem(s).

What to do?? I looked for a router to replace mine but I wanted to be sure to get a new router with asynchronous NAT, as this is what STUN needed, and STUN is what SIPPHONE/Gizmo needed. Finding a router I could be certain was asynchronous NAT wasn't easy. What was easy was flashing my WRT54G with aftermarket firmware to see if that might fix things for SIPPHONE.

Result? Yes, after replacing the firmware in my Linksys WRT54G with non-Linksys firmware I can now have ATA devices (AC211 and 6011S) and or the N800, on the private side of my router (no longer a pure Linksys) and use GizmoProject / SIPPHONE. I used the popular DD-WRT. This is not an endorsement of DD-WRT, I am simply stating what I did.

I took many hours of troubleshooting and digging through many forums to formulate the solution. No place had I read specifically to do what I ended up doing. It was a culmination of information gathered from the Internet and from my experiments thru my neighbor's router which eventually pointed me to trying the firmware swap. I suppose a different router make and model might have worked also, but that was a crapshoot if I had to buy every router model trial and error. (I guess I could have purchased a WRT54GS.)

I see where the OP ( godd ) mentioned his router model. I don't have specific information about that router, but if you are having audio-in or audio-out problems with SIP it is most likely NAT related. Home routers are designed to block your network so those in the wild can't see anything on the private side. Port Forwarding and DMZ techniques are "supposed to" open up a path, but I can testify that these did not work properly with my WRT54G in stock trim. Another headache is that in order to properly DMZ a device, you must know it's IP address on you private network, and that can change if you allow/use DHCP. Making every IP "fixed" (static) is also a pain in the butt if you change equipment constantly like I do.

BTW- The VOIP firm Sunrocket went out of business in August 2007 and there is much Sunrocket hardware on eBay these days and it can be bought very cheaply. People don't want it, or it is surplus new in the box from retailers who pulled the stuff and dumped it to liquidators. The 6011S is an extremely well build wireless IP Phone, which works well with Gizmo, and other SIP providers once you reconfigure it away from Sunrocket. I have three of these 6011S IP phones, and I sent my buddy a Sunrocket AC211 ATA. I use the N800 or a 6011S or the Gizmo client for Linux or Windows on desktops here everyday. Once I resolved the router issue, all works well. I hope this information helps you.

M5

BTW- the Area775 thing has some quirks (by design). In order for calls to ring you, you are required to provide landline numbers (and or mobile) and have money in your Gizmo account. Calls into your Area 775 # will ring simultaneously all the devices when anyone calls your Area775#. The catch is that if you answer anything but your Gizmo client (or you could also use your N800, or a 6011S) you will have your account debited $2 per incident. Not nice.

If you do not have your account funded, and/or you don't provide "CallWave" the landline/mobile numbers they seek, all calls to your Area775 number go straight to voicemail.

GrandCentral is an option because they can direct calls from PSTN to Gizmo SIP but all calls are screened..... you have to press a key to accept the calls. This is a nuisance.

My solution was getting a number from IPKall. It isn't 100% reliable, but it is 100% free. People who call my IPKall PSTN number ring onto my Nokia N800(with Gizmo), my Sunrocket 6011S(configured for Gizmo), and any Linux/Windoze computers running the Gizmo soft client.

I am not quite sure if Skype and the Gizmo client play nicely together. They might not. I am also not sure that several Sunrocket 6011S devices work properly if they are all on the same private network. SKype will allow many clients running at the same time on a private network because Skype randomly assigned a different port to each client. That way they don't trample one another. I don't think Gizmo does this. I am not 100% sure but I think you CAN reassign ports in the Gizmo soft client. The objective is to NOT have several Gizmo clients share the same ports. Regards, M5.

I just checked...... Gizmo Project on Windoze ( I am running version 4.0 ) DOES allow ports to be changed manually. It is under options>advanced>.

M5

EDIT: There does not seem to be an equiv. setting in the N800 version.

WOW!
xxM5xx, your contribution here is very much appreciated. I learned a lot of new details about Gizmo and SIP in common. Now I can swim in this water without fear to drown.

You said that
Are you sure about that? That's exactly my case - I do not want to spend a penny on it for now and from what I've read, Area 775 number will ring on your softphone without any money involved - here is a quote from their site:
If you are right, than my problem is not a router, it is just my greediness.
Thanks for the IPKall link - I'll give it a try.
Honestly, I do not see a usefulness of having SIP number on N800 - I just want to play with it a little.

Okay, you do NOT have to have actual money in your Gizmo account BUT you do have to have a credit card on file with them ---AND--- you have to provide a valid PSTN phone that will dual ring with SIPPHONE/CALLWAVE or else your gizmo softphone will NOT RING when someone dials your Area775 number.

Without meeting the aforementioned requirements, all calls to your free Area775 number go straight to Gizmo/CallWave voicemail.

I personally see little distinction between giving Gizmo my credit card # and actually depositing $10 with them (with the exception that they could charge my credit card alot more than ten dollars if I am careless or ignorant about how I answer calls ringing in from free Area775). Don't get me wrong, I am not anti-Gizmo SIPPHONE, but I think it is kind of sleazy the way they are doing the free Area775 dual ring/call transfer. The number is free to obtain, but to make it useful you have to pay them, or gamble on the $2 per incoming call thingy. It is a gimmick..... you MUST give them a credit card or deposit funds in the account --AND-- give them your mobile or landline numbers to get the Area775 to "ring" anything. Gizmo is hoping you (or one of your family members) goofs up and answers the landline or mobile so Gizmo/CallWave can charge you credit card $2 for everytime that happens. You won't find out in many cases until you get you credit card statement weeks later. After you do that a few times you will probably smarten up and pay them $3.95 per month for basic Area775, or $7.95 per month for premium Area775, or $12 for a Gizmo Call-In PSTN number for 3 months (all of which aren't too bad a deal in reality). I guess I just feel Gizmo is pulling a fast one with the fine print about the $2 per incident charge if you mistakenly ( or a friend or family member ) answer the wrong "device" when the FREE NUMBER rings.

Gizmo mentions that "free" Area775 service will not work "with hardware". I am uncertain what they mean exactly because my hardware (my hardware IP phone) does ring when anyone calls my Area775 number. What I do not know is if I'd be charged $2 if I pick up the incoming call on my IP Phone ( a reprogrammed Sunrocket 6011S ).

I do not have a credit card on file with Gizmo. I did give them $10 back in August. I have two IPKall number which both ring my Gizmo SIP, which ring my Gizmo softphone on PCs and my N800 --AND-- my 6011S IP phone. The IPkall numbers are PSTN numbers and they are free (truly free). I also have a Grand Central number in MY area code which was also free (but there is that screening process with Grand Central). The Grand Central number rings my Gizmo also (on the softphone and N800 and 6011S IP phones). All in all it is pretty nice....that and Skype-In and Skype-Out and I have zero need for a landline service and all the taxes the US puts on POTS telephone service. I do pay heavy phone taxes in the form of mobile phone service for now, but that will change when I transition to T-Mobile to Go in a couple months.

BTW- if you want people to have a way to ring your GizmoProject softphone (or SIP hardware) from the POTS network, Gizmo (and FreeWorldDialup) provide 20 telephone numbers around the USA that your non-geeky friends can call, then they enter your Gizmo SIP number ( the 747 number ) and it will ring your Gizmo softphone or hardware. This is nice. It is a way for POTS users to ring your SIP with no cost to you (and no cost to them if the PSTN number they use is not a long distance call for them). Here is a link to the 20 access numbers:

http://www.gizmoproject.com/access-numbers.html

Gizmo has something they refer to as All Calls Free ( ACF ). There are things that must be met to get that to apply. I won't get into the details here. You can read about it here:

http://www.gizmoproject.com/learnmore-allcallsfree.html

Hope this helps.

M5

I completely agree with you about credit card issue - I gave them virtual number that expires this month and did not setup landline or cell phone with them. I thought it is NOT necessary in order to get calls on 775 number. But you are right - in order to use this service, backup "hard" number is needed.
I will try IPKall, as you suggested above after I cure my tablet - it died this morning for no reason - I will open a dedicated topic in Troubleshoot section.
BTW, what POTS stands for?