SIP in higher education

[Candace Holman <>]

Pretty ambitious!  Lots of us wish we could use Skype with SIP.  Thanks 
for providing all the details.

Candace

John Todd wrote:
> > Though dual-mode cell and voip device convergence is nothing new, it 
> > is a little hard to obtain, with many companies promising products 
> > that are yet to be released or just for home consumer use, such as 
> > Motorola's Residential Seamless Mobility Gateway for example [1]. EQO 
> > has released a cell phone plugin "which runs on your computer, 
> > connecting your Skype user account to your mobile phone" [2]  So a 
> > call from your cell to a Skype buddy on your buddy list is delivered 
> > over regular wireless phone services using SkypeOut (PSTN connected 
> > Skype calls).  A bit too Rube Goldberg-esque [4] for my tastes, but 
> > they got the job done.
> >
> > Interesting points from the CNET article [3]:
> > * Instead of phone numbers, you use Skype buddy lists, downloaded to 
> > your cell phone, to contact others
> > * Your buddy list indicates user "presence" as a device capability, 
> > ie whether you can call via Skype or cell
> > * You can place privacy restrictions on your buddy list so you only 
> > get calls that you really want
> > * It's not supported on phones that don't run Java J2ME (like Verizon 
> > wireless service, which uses BREW)
> > * Eqo says that Skype is just the beginning, and they plan to partner 
> > with LinkedIn, MySpace, and others
> >
> > So, are you ready to bite?
> >
> > Candace Holman
> >
> >
> > [1] Roam where you want to!  New Motorola Technologies Break the 
> > Barrier Between Home and Wireless Phone Services:
> > http://www.motorola.com/mediacenter/news/detail/0,,6258_6213_23,00.html
> >
> > [2] Understanding EQO:
> > http://www.eqo.com/download_how.html
> >
> > [3] Service lets Skype users chat on cell phones: 
> > http://news.com.com/Service+lets+Skype+users+chat+on+cell+phones/2100-7352_3-6036663.html?tag=nefd.top 
> >
> >
> > [4] Rube Goldberg
> > http://en.wikipedia.org/wiki/Rube_Goldberg
>
>
> Apologies for mentioning another semi-vaporware item, but this seems 
> interesting and I actually have it running (in pre-release mode.)
>
> This is another Skype add-on, but it converts SIP to Skype.  It can 
> work both ways, but I typically only use it as a one-way conversion in 
> my PBX-like environments.  (SIP->Skype)  It allows me to assign a new 
> SIP URI to users which actually is their Skype ID.
>
> As an example:
>   I have configured here at my workplace a "generic" Skype account 
> that is named something like "tello-skype".  Then, I simply forward 
> (via forking or sequential ringing) SIP calls to this extension, and 
> they ring on the remote Skype account.  If I have configured my Skype 
> Windows machine on 10.1.2.3, then to ring a Skype user called jhtodd I 
> would dial sip: and the system would perform the 
> remapping.  The Skype user "jhtodd" sees an inbound call from 
> "tello-skype" every time I call that destination.  This is useful for 
> treating Skype as a "trunk" to reach users who might have their Skype 
> account running but are not using a SIP soft client.  An example of 
> this in Asterisk dialplan with forking ringing might look like this:
>
> ; 2405 is John Todd's SIP phone, 2505 is his SIP softclient,
> ;  and "jhtodd" is his Skype username.
> exten => 
> 2405,1,Dial(SIP/2405&SIP/2505&SIP/jhtodd@skype-gw1,40)
>
> and in sip.conf:
>
> [skype-gw1]
> type=friend
> host=dynamic
> nat=no
> secret=blahblahblah
> canreinvite=no
> disallow=all
> allow=ulaw
> allow=alaw
>
>
> What you need:
>   - a Windows machine
>   - the Skype software for Windows
>   - a "generic" account for Skype
>   - the PSGW software with the "any Skype destination" patch(*)
>
> Upside:
>   - does not require dialing party to use Skype
>   - does not require knowledge of Skype password information
>   - does not require "opt-in" by Skype user population
>      other than knowledge of Skype username for desired destination
>   - works without modification to any SIP infrastructure systems
>
> Downside:
>   - client handles only one call at a time
>   - does not relay presence information
>   - audio-channel only
>   - requires Windows
>   - not a free product
>   - audio quality is jittery sometimes (turn off "allow skype to 
> modify audio settings" feature to minimize problems)
>
> (*) This is not part of the release that is typically available on the 
> website, but if you ask the author it may be available pre-release.  
> I've asked him when he's going to include this option in the general 
> distribution, but he hasn't replied yet.  The cost of the software is 
> $29.95 for a single user license.  The current shipping version of the 
> software does static mappings, meaning that the SIP AOR is not 
> converted into the Skype AOR, which is very restrictive and does not 
> permit the SIP server to have the "intelligence" for routing.
>
> Hints: The Windows firewall on the Skype host needs to be configured 
> correctly for port 5060 to allow queries from your proxy but disallow 
> from everywhere else.  Lots of codecs are supported, but I've only 
> tried G.711 with any success or quality.  echo123 on Skype is a good 
> test destination.  It could be possible to run multiple instances of 
> Skype environments on a single CPU by implementing vmware machine and 
> then cascade through them with some fairly simple Asterisk or SER dial 
> rules.
>
> Discussion: I am not a big fan of Skype, because of it's proprietary 
> nature.  It's a great protocol, but it's closure to external 
> connections makes it "unfriendly" to the goals that it seems are 
> embraced by the SIP.edu community.  However, sometimes pragmatism 
> overrides idealism, and we are forced to break out the tongue 
> depressors, waffle irons, anvils, and duct tape and pay homage to Mr. 
> Goldberg by making some contraption that connects two otherwise 
> incompatible systems.
>
> JT
>
>
> --
> John Todd
> Networking, Tello Corp.
>
>   +1-650-581-2405