SIP vs. Skype, Making the "Open" Choice

techie34290 writes "If you were to make the choice between SIP and Skype for Linux, which one would you go for? Matt Hartley from MadPenguin.org says to opt for SIP. Why? "One tidbit of information that most people are not likely aware of is that when you install the Skype client, it will drain system resources by running as a supernode from time to time. Granted, this is not always the case; however, the very idea of my PC having its resources tied up for someone else's phone call is frankly maddening to me."

Isn't that the point?

[dizzoug]

The sacrifice you make to have a 'free' phone service is your system resources. Without donating your clock cyles, you would have to pay skype to use servers that they would otherwise have to provide. And yes, if your system can handle it, it will act as a supernode from time to time. It is your choice, but very few things are truly free.

Re:

[FooAtWFU]

I seem to recall this being the reason that a number of locations were reported as considering banning Skype in a recent Slashdot story.

Re:Isn't that the point?

[Sylver Dragon]

I can confirm that this is occuring. I work at a University, and while they do not, technically, ban Skype outright, they might as well. The reason for this is that Skype likes to put computers on our network into supernode mode (considering the bandwidth here, I understand why it happens). The problem is that it starts eating bandwidth like mad, and reduces bandwidth available for other users. So, in order to combat the bandwidth hogging, Skype traffic is throttled at the firewall; it is still allowed to connect and use some bandwidth, but you can forget video conferencing. And before I get any of the "but, but, but...student's rights" type posts: we are a private university, i.e. no public funds; the students have the right to go elsewhere if they don't like it.
Actually, this is a rather timely article, as I am working on setting up a video conferencing room and need to find good free/cheap options.

Re:

[shokk]

Someone changing universities because they can't use Skype doesn't have their head screwed on straight.

Re:

[Knetzar]

You're right, they should chage each student more so that the students have the right to use the internet any way they wish.

Re:

[sjames]

if it's burning THAT much bandwidth, they have few choices. They can Ban it, limit it, or charge all students more for their net connection to accomodate a few. I'd say they're being quite reasonable by choosing the middle option.

Re:

[sjames]

Where do you get that? Bandwidth costs money. Students usually aren't swimming in money. So, it's better to limit bandwidth on a single app than to raise prices.

There's lots of bogus anti-Skype FUD

[billstewart]

I've never been sure of why there's a lot of anti-Skype FUD out there, but there is, just as there was a lot of FUD about the Scary Security Risks of USB flash-drive dongles. I think it's mostly columnists copying each other's memes so they've got something Serious to write about.

Skype doesn't use a lot of bandwidth, so even if you're running in supernode mode it's not going to make a big difference, except maybe if you're on a home DSL with 128kbps upstream bottleneck, and the FUD's targeted at busines

Re:There's lots of bogus anti-Skype FUD

[GreyPoopon]

Skype doesn't use a lot of bandwidth, so even if you're running in supernode mode it's not going to make a big difference, except maybe if you're on a home DSL with 128kbps upstream bottleneck, and the FUD's targeted at businesses and universities that have much larger connections (i.e. places that make decent supernodes.)

Uh, if the supernode mode is enough to cause performance problems with a single user over a 128kbps upstream connection, it's likely to cause some noticeable problems at a business with thousands of users running Skype -- even if the connection to the internet that they share is a very large one.

Re:

[Greyfox]

Yah. Something kind of similar with sip (or IAX) is fwdout. [fwdout.net] You share your landline for local calls in return for use of the network.

Of course these days it's pretty rare that the person you're calling does not also have a computer, so you could make a free point to point call with sip just as easily. You just need to know the IP address of the person you're calling, or they can get a free number for internet calls from Free World Dialup. [freeworlddialup.com]

Re:

[Greyfox]

Aah yes good point, I neglected to mention e164.org. e164.org lets you register your phone number and associate it with a voip address. They also have a handy little script that lets Asterisk search e164 to see if it can find a match for the phone number. If it finds one it can route the call over the Internet.

My asterisk setup first checks to see if it's a free local call (800, 303 or 911) and routes over the landline if it is.

Then it checks my local set of DUNDI peers to see if any of THEM know where

Re:Isn't that the point?

[Vihai]

No, it isn't. No wonder there is no "SIP" server, managed by a "SIP" company.

SIP is a technology while Skype is a service, provided by a single company with a proprietary technology.

The difference is absolute.

You could provide the same exact service Skype is providing with SIP. Did you ask to yourself why there is no such service? Because it would be much harder to lock your customers in with SIP. SIP is already peer-to-peer for what concerns audio streams.

Re:

[CharlieHedlin]

You are right and wrong. Skype is both a service and a technology.

Thanks for the differences; there are even more

[postbigbang]

Thanks for pointing out the obvious thing that people forget. Let me go further and say:

1) Skype is closed and a single metamodel that's been implemented nicely and virally (not that it matters)

2) SIP (and ENUM) are perilously prone, not because they're protocols, but how the protocols are implemented, to shenanigans. SIP is natively text, and ENUM is a DNS method that's prone to spoofing and other problems. For now, Skype wins only because few people know how it works at its deepest levels.

3) Skype isn't as extensible as the SIP/ENUM combination, and it makes one dependent on a single (if diverse and highly peered) network.

4) SIP and ENUM don't care about the service and are largely service neutral (some coming problems, here, though, as it doesn't do nice things like embue codec choices, encryption/authentication means, and other security niceties).

5) Skype is one closed vendor, very few business partners, while SIP is a technological infrastructure that invites whomever to do whatever.

Re:

[STFS]

Did you ask to yourself why there is no such service? Actually there is: http://openwengo.com/ [openwengo.com]

Wengos application is GPL and it uses SIP as its protocol. Behind it, there's a french phone company I believe which seems to think that this may somehow pay off for them (I don't know much more about their business model though).

Re:

[phatmonkey]

Yes there is. [gizmoproject.com]

Re:Isn't that the point?

[Fordiman]

Actually, the only reason this is done is that, for two computers without the ability to open up a listening port to Internet, they have trouble contacting one another. So, Skype uses one of its members as a through-way for a call. Calls done in this manner are reduced in quality to reduce the third-party's overhead (since you're essentially leeching off another human to do it).

It would be very nice to find a way to make a TCP/IP connection without having a listening port. I believe it could be done, still using the third party for setting up the connection, but using a spoof of some nature.

A possible way is: Caller (C) requests a connection via the Skype Network (SN) to Reciever (R). R is connected to SN, but has no incoming connection capabilities, so SN requests a transitional connection from a third party (T). C and R both call T. R tells T which local port its connection is on. T spoofs C, telling C that its IP address and port are those of T. T also spoofs R, telling it that its IP address is that of C, connecting on R's port(R effectively becomes the server, the router's outgoing port becoming the incoming port). R and C, knowing this will happen, do all the syn/ack stuff manually.

I'm not well enough versed in TCP/IP to do this (or even say whether it can be done), but perhaps someone is.

Re:

[Fordiman]

Well, as I understand it, Skype's pretty derned smart. I do believe it checks all reasonable avenues of connection before it resorts to third party connection.

Meanwhile, a program can't expect the router to follow port-binding rules, necessarily - though, it can always check.

Re:

[Rodness]

I've done a lot of research on Skype lately. If you're running as a supernode, it only uses about 6k of bandwidth up and down, it doesn't monopolize your network connection.

And if you want to make sure you'll never be a supernode, just make sure you're behind a firewall/NAT. The criteria for being a supernode are fast processor, available memory, and fast UNFIREWALLED connection. It's very easy to make sure you're not a supernode by using a firewall. It's really not that big a deal, and certainly not wo

Success of Skype

[dyefade]

It's getting to the stage now where I know people who say "Skype" when they mean "VoIP/SIP". Admittedly, it's early days in terms of adoption of the technologies, but this is a little worrying. Seems like very few people in the real world have any concept of open standards etc.

Re:

[account_deleted]

Comment removed based on user account deletion

Typical.

[SanityInAnarchy]

Happens with entirely too many things. Google is about the only one that I like. iPod, MySpace, PowerPoint, Tivo...

So yes, people sell "Skype headsets" or "gTalk headsets", and we don't notice when there start being "Xbox Live headsets" which actually use a different plug. "PowerPoint" remotes. "iPod" cables. MySpace as a noun -- not "My MySpace page", but "MySpace: <url>".

Language these days is really getting abused. I don't know how recent it is, but it certainly feels Orwellian. Keep oldspea

the very idea

[thrillseeker]

of my PC having its resources tied up for someone else's phone call is frankly maddening to me

... but I have no problem with tying up someone else's resources when it's for my convenience ... ?

Re:the very idea

[Have Blue]

He'd prefer that the supernode feature be removed entirely and Skype calls only ever consume the resources of the consenting parties directly involved in it.

Re:

[Shadowmist]

Wired ran an article on Skype. The reason that Skype can run as it does with the majority of users not going beyond the free service is that the supermode makes it possible to run a bittorrent style phone system (my choice of words). Remove it and Skype effectively ceases to exist as a commercial venture. The free solutions simply can't provide the services that Skype or anotehr commercial provider does.

As an aside, I believe Nikotel uses SIP. The software I have from them as settings for SIP server

Re:

[gEvil (beta)]

Didn't you get the memo? It's okay as long as they don't know you're using their resources...

Re:

[jacksonj04]

I was wondering if the author ever uses BitTorrent. Because there's obviously a huge difference between someone using your resources to exchange data over the internet, and someone using your resources to... uh... exchange... umm...

Re:

[stuuf]

Actually, the difference is that BT lets you throttle or even disconnect torrents on an individual basis, while Skype is all-or-nothing. With Skype, you have no control over when you'll be forwarding some random person's phone call, but you can only send data to BitTorrent peers if that specific torrent is running, and you can always control how much bandwidth you allow them to use.

Supernodes "maddening?"

[cbreaker]

"the very idea of my PC having its resources tied up for someone else's phone call is frankly maddening to me."

Well, boo hoo. It's the way the system works. I seriously doubt any significant system resources would be used up for other people's calls. When you make your calls, it happens to other people. It's a give-pull situation where everyone has to share resources in order for the system to scale with the number of subscribers. Would you rather have nothing?

Doesn't play well with others

[Rob T Firefly]

"One tidbit of information that most people are not likely aware of is that when you install the Skype client, it will drain system resources by running as a supernode from time to time. Granted, this is not always the case; however, the very idea of my PC having its resources tied up for someone else's phone call is frankly maddening to me."

Erm.. that's kind of the point of decentralized P2P, you leech.

Re:

[svanstrom]

Yeah, but Skype isn't advertized as decentralized P2P, so most people won't know that that's how it works when they install it; and most people using Skype doesn't even understand what decentralized P2P is.

IM-programs have for years _NOT_ been decentralized P2P-based, and Skype is largely competing with other IM-solutions; so it's not like people expect it to be P2P in the sense that their computers are used for other peoples filetransfers etc.

Re:

[svanstrom]

That didn't come out exactly as I meant to write it, so please, read what I meant to write, not what I actually wrote.

But, hey, that just proves that average people don't get a chance to actually learn how e-stuff's working, as people like me write confusing stuff in forums like /. =)

Re:

[Rob T Firefly]

You made your point well enough that I could understand it, which might be cause for worry actually. Get thee to a therapist!

But seriously, as much as I appreciate the fact that Average Joe Sixpack can't really be bothered learning anything about what the magic bleeps, sweeps, and creeps inside his computer box are really doing, I can't have much sympathy for him when he starts complaining about stuff he chose to use working as designed. Computers are nearly as ubiquitous as cars nowadays, and people who

What a bunch of crap...

[rthille]

Sure, I prefer open solutions, but to say that Skype will drain your system's resources is just crap. A simple consumer firewall between your skype-running PC and the internet will prevent Skype from using your PC as a 'supernode'.

Re:

[Jaseoldboss]

That has been my experience too, I'm behind a NAT router and I've never had any problems with bandwidth / resource hogging.

I wish Skype was open source too but I use it because it runs on my PocketPC easily whereas not many other VoIP clients do.

Re:

[spinkham]

Yes, skype can traverse NAT, but cannot be a supernode for others when it is behind NAT. That is what your parent post was saying.

So, now the shoe is on the other foot?

[Hektor_Troy]

So - it's cool if others donate their time (and other resources) to give you something for free (SIP - both the protocol, but also a LOT of the programs for it), but if YOU have to give something of your resources (like bandwidth) for free - well, that's something COMPLETELY different.

Somehow I don't see how that works.

Sure, Skype is proprietary - but I've never paid anything for it (except bandwith), and it works just fine for me, so - to me at least - it's free (monetary, not libre). SIP - well, never tried anything that worked just as well as Skype, so it's libre, but it's not free to me (costs me and others resources like their and my time to get it working).

I don't really see the difference (but I'm not a fanatic proponent of Libre software).

Re:So, now the shoe is on the other foot?

[Lussarn]

Skype is a black hole. Sure I could open it up in my firewall but why would I? As I understand it skype could easily use a couple of gigs of bandwidth every month with no way to control it or even measure the usage. I could probably set up a couple of QOS rule to tame it down but that would take time, and the only benifit I would get is letting an unknown protocol connect to my home computer through a closed source app.

I'm also sick and tired of installing all these proprietary apps, each with it's own protocol and from the looks of it every couple of years there is the next big thing you need to install. Not because it's actully better but because someone you need to write/talk to has it. No thanks, we need something open and documented. Then every company could make their own client, brand it, sell it and popup commercials all day long as they wish. And I could use something smaller OSS that suits my needs.

And I would gladly contribute both bandwidth and cpu usage. But never for skype as it stands now.

Re:

[Infernal Device]

because someone you need to write/talk to has it.

Well, when everyone magically switches over to free and open, you can join in. Until then, I guess we'll have to do without ya.

Re:

[Lussarn]

I don't know where you got the free from as I didn't mention it. Maybe you like making things up to make your nonsense argumentation hold water.

Re:

[arose]

Sure I could open it up in my firewall but why would I?

The problem isn't opening your firewall for Skype, the problem is closing it.

IAX?

[zotz]

"If you were to make the choice between SIP and Skype for Linux, which one would you go for?"

IAX I guess...

if all of that stuff was legal down here. That is not so clear.

all the best,

drew
http://www.ourmedia.org/user/17145 [ourmedia.org]

Re:IAX?

[ncw]

Yes!

Sip plays merry hell with firewalls. Don't even think about it unless you've got a VPN back to your sip server! If you have then it works great. The new Nokia E70 phone connects to our office Asterisk server via SIP and works very well ( http://europe.nokia.com/phones/e70 [nokia.com] ).

IAX2 goes through NATed firewalled links just fine. It is much easier to configure if you are on the move (or your users are).

I wouldn't touch Skype with the proverbial barge pole given its closed nature.

Re:

[RGRistroph]

I agree that IAX2 is the way to go, because of SIP's firewall and NAT problems.

I have even had trouble with SIP over some VPNs.

However, there are not as many IAX2 softphones available, as there are for SIP.

Suppressed Information + Fear

[DingerX]

Article translation:
SKYPE: OMG! A supernode! you gotta be kidding me! You mean if I turn it on, it might use more bandwidth than I imagined? And if you use it to make phone calls, and lose your password, you probably won't get your money back.
Gizmo: Well, at least it uses SIP.
Full Open Source SIP stuff: Now this is the way to go. Too bad there's not much out there anybody else uses.

Okay, it's Mad Penguin, but who exactly are we preaching to?

Supernodes. Yeah, skype does that, and it can be a pita. If skyp

Re:

[Isao]

The #1 reason why I use Skype over SIP: It's encrypted. At least that's what they tell me.

And what they tell you is true. No one has access to the keys except you and the party you're Skyping. Oh, and Skype.

Hmmmmm.

Re:

[DingerX]

Actually, that was my point. Now that Ebay owns skype, and the FCC apparently mandates VoIP backdoors, who knows what's going on with Skype encryption? In any case, with skype, the weak point doesn't even have to be the encryption; the user password delivers "the keys to the kingdom" with no oversight. Skype delivers the private key based on a relatively unsecure password, and there's no way to tell how many clients are connected under the same username, or even if someone tried a brute-force attack on a pa

gtalk

[hey]

Its worth considering Google Talk (Jingle protocol).
It uses XMPP (Jabber) then kicks up to Jingle for voice.
Nice.

Re:

[hanssprudel]

Are there any linux implementation of XMPP + Jingle? Google [google.com] seem to say otherwise...

What Skype provides very nicely is something that a) I can use in Linux b) My friends can easily install and use in Windows. The a) part is true of various SIP implementations, but I have never seen one that was one-click-and-run in Windows, while the b) part seems untrue regarding all the other IM-with-voice applications (including gtalk).

Re:

[msh104]

jabbin 2.0beta ( http://www.jabbin.com/ [jabbin.com] ) allows you to talk to jabbin users.
I also heared that kopete has experimental jingle support, but that not very usable yet..

Re:

[msh104]

"allows you to talk to jabbin users." has to be "allows you to talk to google talk users."...

Re:

[arose]

Are there any linux implementation of XMPP + Jingle?

There was some talk about Gaim 2.0 having such functionality, no idea what became of that.

[..] I have never seen one that was one-click-and-run in Windows [..]

Gizmo [gizmoproject.com] might be what you are looking for.

Re:

[kripkenstein]

Are there any linux implementation of XMPP + Jingle? Google seem to say otherwise...

You can use Tapioca [sourceforge.net] on Linux. Get your Windows friends to use Google Talk instead of Skype, and you are good to go with VoIP.

Control freak...

[Vellmont]

the very idea of my PC having its resources tied up for someone else's phone call is frankly maddening to me

This strikes me as an attitude of someone who can't stand the idea that he's not in control of everything (which you never are). The real question is, does it use any significant resources that effect what you're trying to do at the time? Frankly I don't really care about 20-50 megabytes of memory, or 5% of my processor usage, or even 100% of my idle processor usage. Those numbers are all low enough that you'd more than likely never notice or miss those resources. I would be concerned if the app started taking up hundreds of megabytes of memory, or 30-40% of my processor time, or locked up system resources that interfere with other apps I'm running. So which is it? The author didn't provide us with any of that information, only the extremist position that ANY useage of his computers resources that wasn't for him was unacceptable. What a useless article.

Re:

[silas_moeckel]

Funny I have a fairly smart firewall meaning PC's at my home and be used as supernodes leave skype turned on for any ammount of time and I can watch my uplink bandwith max out to what QOS allows for unknown traffic. I run SIP with ENUM and strangley anybody else with SIP and ENUM can call be for free without any other service provider involved in the call past ENUM. Sure you can tap the phone call but you can tap land lines and Skype for that matter.

Re:

[Trogre]

Frankly I don't really care about 20-50 megabytes of memory, or 5% of my processor usage, or even 100% of my idle processor usage. ... until you receive your next power bill.

jabbin

[msh104]

I recently discoffered jabbin.
http://www.jabbin.com/int/ [jabbin.com] it's free as in speech, and has voip support.
perhaps he should give it a try. there are windows, linux and mac releases.

What about the advantages of being a supernode?

[demallien2]

Of course, this wonderfully balanced, well-researched and well-written article did overlook one rather important point: The whole supernode concept lets Skype get through nearly ANY router configuration imagineable. I beat my head against a brick wall for three months trying to convince my father's ADSL modem to let through voice comms for a SIP client. No go. The only way to get a VoIP solution through was to install Skype.

Cringely on Skype

[richg74]

Back in July, Bob Cringely at PBS had a column in which he talked about Skype [pbs.org] and its use of super-nodes.

I'm surprised to hear people still talk...

[xxxJonBoyxxx]

Frankly, I'm surprised to hear that people, especially Slashdotters, still talk to each other. I'm guessing this "voice" thing is some kind of emergency backup in case your email and instant messaging clients go down.

Why I initially chose Skype...

[emag]

One word: laziness

Longer reason:

I really didn't want to have to learn the intricacies of a protocol in order to get everything up and running. I'd been seeing various things that at least *implied* that I'd have to start mucking about with firewall rules in order to get SIP running. This was something I had zero interest in doing at the time. I also wanted something that would be cross-platform in an easy manner (I was looking at this so my manager & I could keep in touch while we both worked from home, without using cell minutes or LD charges....him Windows, me Linux).

Then I needed to be able to call out to POTS lines. Enter SkypeOut. No monthly charges, just a relatively low per-minute charge (which was OK, I still, after 16 months, haven't used the initial 10 Euros I put in). Then I needed people from work to be able to contact me, and I didn't want to give them my cell or house lines. Enter SkypeIn. $38 for a full year, with voicemail. Usable anywhere. That was a big draw. So long as I had a network connection, I could head off to a family member's place for a long weekend out-of-state, and still be reachable. No problemo spending 8 hours with sun and surf in the background and me being several hundred miles away...

And then things soured... I tried to renew my SkypeIn number. Failed. Again and again and again. Skype's purchase process is rather....opaque. They use a variety of 3rd party payment processors, and all Skype can tell you is "success" or "failure" until you start bitching about being unable to pay. Though don't expect an immediate response, as it will take up to 4 days. And then, if you're like me, you'll be told that your NATed laptop running Linux on a static IP with no proxies is "an anonymous proxy", and be told to check you IE settings to ensure you're not using a proxy (yes, IE settings in Linux...). You'll be told to, get this, try a different ISP. And even though you'll have already tried multiple credit cards, and multiple browsers with them, you'll be told to try another credit card, or another browser. Or worse (IMNSHO), another payment method that until just recently announced, had practically NO consumer protections (way to pay, pal!).

Ultimately, I ended up with access to work's terminal server, and after one too many complaints from the muckety-mucks who'd already been given my cell number (remember I didn't want to do that?) because I couldn't renew my SkypeIn, I decided that I could make a business case for using company resources for attempting to renew. And....it worked. NFC why, but it did.

So, now I have about another year to come up with another solution that'll work for me on random networks, doesn't require special hardware (other than a headset or speakers+microphone), and doesn't have recurring monthly fees, as I don't actually make calls every day, or even once a week. SIP still gives me a headache just trying to wrap my head around. Trying to figure out WHICH providers offer WHAT parts of what Skype offers as an all-in-one package is something I tend to just grow bored trying to research. Some of the more promising-looking clients seem to be geared towards specific providers, while others leave you trying to guess who to go with. Ick. I really don't want to stick with Skype having experienced the bad side of things, but I'm afraid momentum an just how unfocused SIP solutions are for what I want will force me to stay.

(Let's not even get into the whole Skype's Linux client lagging way behind their Windows client, with the Mac client having leapfrogged Linux at some point. There HAVE been a few betas that have finally brought support for ALSA, and some UI improvements. Still miles behind Windows & Mac, which is frustrating, but there's been at least some progress now almost a year after their last major Linux release)

Re:

[Malc]

No problem for me with SIP. I think my SpeedTouch 546 ADSL modem was already configured for IPQoS for voice communications. I plugged in my Vonage router behind it and had no call problems, even when swamping my line downloading stuff. Skype OTOH hand seems to trip up as soon as anything hits the CPU or bandwidth.

Re:

[emag]

Ok, so if I have specific network hardware on a specific network, with specific additional hardware from a specific provider that charges monthly fees, SIP will be rock solid? Care to address my original points of:

* random networks
* no special hardware
* no monthly fees

I could add to that the implied points of:

* Not having control of the network or hardware
* Not having control of the firewalls

though those could reasonably be assumed to be part of the "random networks" requirement.

Re:

[mnmn]

Wow thats a long reason.

Given my laziness, can you give us an intermediate-sized reason?

Re:

[liloldme]

which was OK, I still, after 16 months, haven't used the initial 10 Euros I put in

Did you know that your 10 euros will expire (probably fairly soon). I put 20 euros in, only have used 2 euros so far (some life changes that didn't require me to make that many international calls anymore plus Skype quality for intercontinental calls is so abysmal I ended up using a more "traditional" voice over IP phone service [cheaper than Skype too!!] instead).

My left-over 18 euros is about to expire in 4 months. Be

Hmm... SIP of course

[guruevi]

Skype is a closed-source resource-eating protocol. SIP is an open, standardized protocol which projects like Asterisk use. I think telephony should be a PPP (Point-to-Point Protocol) and not a Kazaa-like P2P (Peer-to-Peer protocol). First of all: what information passes the supernodes? Can anyone see or analyze who you're calling, when and where? Second: what is the bandwidth usage? I can call SIP through 56k, can I call Skype as SuperNode on 56k?

Audience

[Splinton]

Skype is the only proprietary bit of software that I use, but I am reluctant to use another simply because the rest of the known world (known to me, anyway) are using Skype. So if I want to communicate with them, I have no choice BUT to use it.

I would desperately love to use an OSS version, but I can't do so without severely limiting my contact with my friends/relatives.

One Important thing....

[Toreo asesino]

I actually use Skype solely for it's paid-for services (SkypeOut, SMS, etc) as I live abroad, and don't want to pay extortionate rates for international calling.
This isn't covered in any SIP clients that I'm aware of, thus making this debate irrelevant for me at least. My only gripe with Skype for Linux is that they haven't ported over the SMS functionality yet - it, for me is a reason on it's own to use Skype.

Re:

[amorsen]

I actually use Skype solely for it's paid-for services (SkypeOut, SMS, etc) as I live abroad, and don't want to pay extortionate rates for international calling.
This isn't covered in any SIP clients that I'm aware of

It's certainly not convered in the client, but there are lots and lots of providers, and they'll work with any client. With Skype you're stuck with one provider. Can you even bring your old phone number to Skype?

Re:

[Toreo asesino]

Well, my point is that with Skype can call any land-line in any country at local rates, all natively supported by client, protocol, and provider seamlessly. I don't doubt it would be possible to do something involving SIP, but why bother when it's been handed to me on a plate?

I'm open-minded; if there's a package/client which allows me to call & text international numbers at local rates, and that just-so-happens to be running on SIP, then fine - I may switch over if it's any good. Otherwise Skype works

Re:

[amorsen]

Well, my point is that with Skype can call any land-line in any country at local rates, all natively supported by client, protocol, and provider seamlessly. I don't doubt it would be possible to do something involving SIP, but why bother when it's been handed to me on a plate?

What is so hard about typing in a server name, a user name, and a password?

Re:

[Micah]

I live abroad too, and have used both Skype and Ekiga on Linux.

Actually Ekiga with the diamondcard.us service is cheaper -- 1.7 cents a minute to the States vs. 2.3 cents with Skype. So you certainly have a choice.

Having said that, I still usually use Skype. I've had some sporadic trouble with Ekiga, and my GF uses Skype, and isn't really computer literate so I don't want to talk her through setting up a SIP client ...

Ekiga port for Windows?

[TheSync]

If someone would port Ekiga (http://www.ekiga.org/ formerly GnomeMeeting) to Windows, there might be some hope for SIP!

The key to Skype and SightSpeed (www.sightspeed.com) is that they are cross-platform and have solution to the NAT problem. But they are both non-standard. And they both work really well :)

Ekiga has a solution to the NAT problem using STUN servers, but until someone writes a Windows port for it, there will not be massive usage of Ekiga.

You guys are kidding, right?

[glomph]

Skype is a closed secretive disaster. The community RANTED when MSN/AIM/Yahoo messenger played games to cut out client choice (Gaim, Trillian, et al.). If you want simple, use Gizmo ( http://www.gizmoproject.com/ [gizmoproject.com] ) which has a very economical and functional interface to the regular phone system (POTS). Even cheaper, try http://www.voipstunt.com/ [voipstunt.com] or http://www.freecall.com/ [freecall.com]
All of these are street-legal SIP, and you can use any SIP-capable device you like, or use your computer if you want to.

And of

OMG SHARED RESOURCES!

[Blakey Rat]

Granted, this is not always the case; however, the very idea of my PC having its resources tied up for someone else's phone call is frankly maddening to me.

This same guy probably runs BitTorrent and the Blizzard Downloader for WOW with no complaints.

What it comes down to is that Skype plain has better sound quality. It sounds better and with less latency than all the competitors I've tried. Period.

Whatever you select

[Z00L00K]

will cause some drawbacks. The SIP protocol is unfortunately not very firewall-friendly and may not work well without some firewall hacking. The firewall problems are mostly due to the fact that it's relying on multiple UDP ports for the voice transmission. Skype on the other hand seems to be bypassing firewalls with ease.

A few downsides with Skype are that it may act as an intermediate for other callers and it is relatively CPU-hungry.

A better protocol than SIP is actually the IAX2 protocol (Inter-Aste

Better reasons

[VincenzoRomano]

Maybe there is some other reason to choose SIP. It's openness (as in OPEN).
You can choose you favouite service provider (even more than one) and your favourite software (even more than one).
Yet, if you dare enough, you can run your own service or write your own SIP client.
Nothing of this can be done with Skype (and similar initiatives).
Some more interesting considerations about Skype can be found at here [pbs.org], written some time ago by Bob Cringely [wikipedia.org].
And if you find these latter things interesting, you'd give a

Skype doesn't use resources if it's not running

[Matt Perry]

One tidbit of information that most people are not likely aware of is that when you install the Skype client, it will drain system resources by running as a supernode from time to time.

Cry me a river. Shut down Skype when you aren't using it if you don't want to share your bandwidth. The system works because of tradeoffs and people acting as supernodes.

SIP providers and Skype

[tttonyyy]

Well, the problem with SIP and Skype is NAT. The phone/computer doesn't know it's WAN IP to establish connections with other phones, and there aren't necessarily inbound UDP ports open to route UDP traffic to the phone.

NAT routers temporarily accept inbound UDP packets on a port when there has been an outbound UDP packet on that port (aka UDP pinholes). So you get a working UDP "connection" (well, stateless ;) ) both ways once you've estabilished an outbound connection. For VoIP with both users behind NAT, however, this is unlikely to work.

Skype gets around this by using computers that aren't behind NAT to route traffic between two phones that are behind NAT. So if everyone was to block this behaviour, Skype just wouldn't work for NAT users. It requires some community spirit (even if this is unintentional on the part of the user).

SIP systems often employ STUN servers that allow a phone/computer to query the server to find out what its WAN IP and NAT type are (and use the query itself to open up temporary UDP inbound ports on the router - something that works with all NAT types except symmetric).

There's a description and some pretty pictures of how STUN works here: http://www.newport-networks.com/whitepapers/nat-tr aversal3.html [newport-networks.com]

In addition, SIP is also an open protocol, so there is nice free open-source software available (Asterix) to allow you to set up your own home switchboard (calls from different outside lines can be routed to different phones - IE, whenever your daughter's boyfriend calls, it can be routed to ring her VoIP phone). Skype is proprietry so you won't get any customisable features like this.

So really, SIP is the way to go if you're a supporter of open standards, and Skype if you want to follow the headless masses. :)

Gripe With Skype

[RAMMS+EIN]

My only real gripe with Skype is that the protocol is secret. This means that no alternative implementations can easily (or even legally, depending on jurisdiction) be created. Want to create a client that doesn't need a GUI, implement one in hardware, make one for OpenVMS, or create one that is verifiably free of malware? You can't without the blessing of Skype, Inc.

I refuse to use secret protocols or file formats wherever feasible, and it's definitely feasible in this case.

Overlay Network

[RAMMS+EIN]

About the only advantage Skype has over the competition is that it Just Works in a variety of firewall and NAT scenarios. About the only trick it uses that no open protocol system uses (to my knowledge) is a peer-to-peer proxying network that is used if direct communication between peers is not possible. It seems to me that such a network can easily be implemented in a generalized (i.e. protocol independent) fashion.

I've been thinking in the direction of a TUN device connected to a proxy node with a globall

Use Asterisk plus SIP endpoint of your choice!

[Chembal]

Just so you know, I started with Skype, and it works just dandy. If it drains away my resources, I haven't noticed it. But, I've recently had the pleasure of installing asterisk at home, and it is the way to go! If you install and use Asterisk, you have the widest choice of phones (including soft phones) and VoIP endpoint providers, and you have the flexibility of changing your mind about any one of those choices at any time without disturbing the rest of the system. In my recent conversion, I converted the whole house to use Asterisk without changing any of our phones. My wife doesn't notice the difference - she just calls normally and it works. But, behind the scenes, I can selectively route different calls to different networks - hard wired or VoIP - to take advantage of whatever route I decide is the best. If any one of those routes starts to irritate me, I can change it without affecting the rest of the system. Try that with Skype.

Now, a common argument you might get against this approach is that it's unneccesarily complicated and requires a dedicated machine. Well, it may be partially true, in that it's more complicated than installing a single SIP or Skype phone or softphone, and the best (IMHO) approach for an install takes a surplus box; however, the TrixBox [trixbox.org] distribution gets you up and running awfully fast, and can be installed onto a crap machine (I'm using a celeron 500). Follow the How-To here [sureteq.com]. The flexibility is worth it. And, if you have a decent net connection and VoIP provider, the call quality even for VoIP is outstanding.

Other advantages are flexibility in call routing. I currently have a digium TDM400P card hooked up in my install, with one module hooked up to the phone line, and the other module hooked up to all my analog phones in the house. (I'll eventually replace some of the analog phones with some nice IP phones when I have the cash.) I could just as easily add SIP softphones connected to Asterisk, if I wanted, but normal phones seem more natural to me, and it's cheap to do with the TDM400P card. I have three inbound and outbound trunks set up, one using the land line, one using VoipJet [voipjet.com] for long distance over VoIP, and one for calls in from and out to the Free World Dialup [freeworlddialup.com] SIP network. I have my dial plan set up as follows:

Any calls coming in from either my old PSTN landline or my Free World Dialup account are routed to my dialplan, which during the day (6AM to 11PM) rings the analog phones. If the caller is blocking caller id, it forces them to enter their phone number first before ringing the phones. At night, (currently defined as 11PM to 6AM) callers are sent to a VRU, which asks them to hang up if they're a phone solicitation, press 1 to actually call us, or 2 to send the call straight to voicemail without waking us up. In either case when it rings the phones, it will go to voicemail if we don't answer. That voicemail can be retrieved either by the phone, by secure web interface, or currently I also have it email me the wav file of the message.

For outgoing calls, I have it set like this: If you dial a seven digit number, a toll free number, 911, or use a 9 prefix before a long distance call (in case my network connection is down), it dials out through the land line. If you dial a long distance number normally (using just 1 + area code + number, or 011 + country code + international number), it routes it through the IAX2 trunk to VoipJet and saves us tons of money. If you dial a 8 or 393 prefix before the number, it assumes you want to call a FWD number, and routes it out the IAX2 trunk to FWD, which would be a direct SIP to SIP call for free.

In summary, it works awesome, and I had the whole thing working in a basic way (PSTN + analog phone + VoipJet trunk) in one Saturday morning. I had rerouted the whole house's phone system and revam

Considerations

[VincenzoRomano]

Maybe there is some other reason to choose SIP. It's openness (as in OPEN).
You can choose you favouite service provider (even more than one) and your favourite software (even more than one).
Yet, if you dare enough, you can run your own service or write your own SIP client.
Nothing of this can be done with Skype (and similar initiatives).
Some more interesting considerations about Skype can be found at here [pbs.org], written some time ago by Bob Cringely [wikipedia.org].
And if you find these latter things interesting, you'd give a

Re:

[CharlieHedlin]

Having written a sipXtapi application and the SipxTapiDotNet wrappers you better be quite daring. If you are it can be very rewarding.

Skype works well, SIP works badly. End of story.

[porttikivi]

I have called a couple of people today with SkypeOut for international calls. I have chatted with individuals and on the company grpup chat. I am behind a firewall in a private address and so are all my buddies. All this is encrypted, except the POTS part of calls. I can immediately call 7 million of online Skype users. I have SkypeOut, SkypeIn (my GSM phone is in another country currently, I have transferred my calls to SkypeIn), I have Skype voice mail, I can send voice messages to any Skype users, I can

Sip? No. Skype? No. Jingle? OK.

[Baloo Ursidae]

Why go with SIP or Skype when Jingle integrates more sanely into existing infrastructure?

There are reasons to use closed SKype

[sideswipe76]

To the utter disdain of companies like Comcast and many telecom people in China, no one has truly figured out how to discern that there is actually skype traffic on their network much less block it -- this goes for everyone from a nosey IT admin, the govt, or an unfriendly ISP. On the otherhand, Comcast has put the kabosh on SIP from Vonage because it is easy to identify. Skype should continue to improve on the efficiency and stealth of their protocol and improve the features of their client. Sadly, I thin

Have your cake and eat it too

[DumbSwede]

Install Skype but delete if from the startup list. I use AdAware's TeaTimer app which forces the apps to ask permission to alter system settings, so I just had to say no. Skype installs, but will only be grabbing resources after I actually use it, and then only if I don't kill the app after I'm done. Actually not using Skype at the moment, using Google Talk and Gizmo. Learning to realy love my Nokia-770

Re:

[Malc]

How long do you think that's going to last? And BTW, that's only N. America.

I just switched my home line to Vonage. I can now call the UK from Canada for no additional cost. Skype doesn't let me do that. Not everybody I know that I need to call has a computer, or wants to be tied to it for calls. I could probably make Skype work out cheaper, but it doesn't have all of the features of Vonage, so right it can't be my primary method of telephony.

Re:

[Firehed]

Fair point. But what about if/when someone creates a thin-client Skype box (in effect, a Skype-equivalent of a Vonage "modem")? I spent $6 on a microphone and have replaced a good number of otherwise-expensive cell calls with free Skype calls (by the way, the free SkypeOut lasts until the end of the year). While I certainly can't speak for you, all of the functionality I really require from my phone carrier is being able to call people, and Skype gives me that.

Re:

[Malc]

In fact I can get this for my home phone system [amazon.com]. It still requires a computer running and the management of that.

I've also seen some 802.11 Skype handsets, which is cool. Although I don't want anymore phone systems (work line in home office, home phone system and mobile phone are already too much).

I will consider what you suggest when Skype is as reliable, feature complete (including 911 service) and easy to use (plug in and go with existing phones, no hassles with credits like they have, and not require

Re:

[Tony Hoyle]

Until the competition let me call a landline through their product for free, as Skype does at the moment, I won't be switching.

I take it you've never actually used SIP then?

Skype is *far* more expensive than 99% of SIP providers (and due to the nature of SIP you can have more than one configured at a time - I have about 5 at the moment). I can call nearly anywhere in the US and europe for just the connection charge.

Re:

[Knuckles]

Anything else you need ? :-)

Encryption :)
Oh, and it's wengo.com, wengo.org is the private site of some dude.

Comment removed

[account_deleted]

Comment removed based on user account deletion

Re:

[thrillseeker]

Yea....a name like 'hahiss' commands MUCH more respect than anonymous coward....

Infinitely more.

Re:

[Malc]

Sound quality Skype-to-Skype is better than anything else I've used, except when the call is breaking up. I have more problems with that than Vonage... if something else is using my CPU, or the other person's, or some random internet thing and we can't talk very well and the better audio quality is moot.

I've had problems with credit cards too. I run two Skype accounts (personal & work) because they won't support anything in the client that will allow me to operate that way. Buying SkypeOut credits fo

Re:

[Malc]

I somehow doubt it. I work from home, run two Skype clients concurrently and often copy 1 GB video files to and from the office. I still have months where I use less than 10GB (accourding to my ISP).

Re:

[CharlieHedlin]

It isn't the latency, but the jitter (the variation of latency). a 600-610ms or 900-940ms latency isn't a problem, but 600-800 is. Most decent sip clients can be tuned to support that, but the providers lock the settings down too far for you to do anything.

Nice troll

[metamatic]

You might get a few people who don't know that Bonjour is simply multicast DNS used to provide chat on your local network.

Re:

[Simon80]

I don't understand why this is even a serious debate here, the answer is a no brainer. Skype is a closed protocol, closed source app, you can only call other Skype users, and only using a softphone. SIP is an open standard that lets you use a variety of different services to provide an address for the calls, depending on the service you can usually call people with a SIP address at any other service, not just people at your own, and you can use whatever client you want to make the call. This can be a sof