What are the strategic implications for Skype and competitors if Skype opens up SIP? As a user I could use Skype "supported" SIP features. That may mean I can ring a Wi-Fi SIP phone device, I may find it hard to scroll my buddy list or obtain the same voice quality as I get with the Skype experience. Would this allow me to receive "securely" (I don't buy the security argument BTW) my SkypeCalls on a corporate SIP device or SIP softphone without upsetting my IT department? If so this would be pretty cool. At the moment unless I have call forwarding, (or Vonage already at home) I can't enable my home landline to ring the office. Wouldn't SIP enable you to ring your Skype almost anywhere? While the call quality would be inferior... the sound would always be better on a Skype soft client or via a Skype enabled hardware device (the approval and integration process is real important).

What if Skype just offered SIP numbers with SKypeIn? Would that make them quickly the largest SIP community and deployment? Could Skype then "shape" the direction of SIP and thus telephony. What happens if Skype introduces their own version of SIP (Microsoft vs Sun on Java)?

Does Cisco fit in the Skype SIP plans? It's a fact that Milk Volpi from Cisco sits on Skype's board. We have examples of both Linksys D-Link router solutions. Jeff Pulver noted back in September last year that they could work a proprietary form of SIP.

Is it appropriate to guess that the SkypeIn system now adds @skype.net to all Skype names to create the Skype SIP identity. So I'm stuart_henshall@skype.net or something similar for them to provide the interconnect. That registry then opens up a number of new opportunities and the ability to substitute "corporate" e-mail addresses for the Skype created dummy address. Thus this would enable connections to corporate registries etc.

I'm not the telecom / SIP wizard, I just write scenarios from time to time. Could a leap take us to using the organization's SIP server to register "internal" Skype clients into the Skype network? All connections outside the firewall would be via the SIP server, and thus the enterprise would have the "security" and functionality of Skype inside. perhaps complements of Cisco?

My real interest in this line of thought began with creating an even larger market for Skype related hardware. Making hardware that is both SIP and Skype compatible will further accelerate Skype growth. It creates a larger pool of hardware that "works" with Skype while sucking more people into the "Skype" experience. The hardware that Skype approves can then focus on better sound, experience etc. Done correctly the price premium would be for Skype approved hardware. Interestingly "consumers" could be the one's paying the royalty via their service agreement. I don't think Skype began with a SIP strategy, in fact many press releases complained that Skype wasn't SIP based in a "how could they" approach. Now in a twist of fate, opening and driving SkypeSIP could bring in many new developers and systems suppliers. It could also prove that Skype has both broken SIP and perhaps ready to press it's own form forward.

Notes:
I blogged 5 million Softphones when SkypeOut was launched. They are over one million SkypeOut customers now. Alec Saunders succinctly put it that they were distinctly breaking inter-op. At the same time Tom Keating asked whether Skype had the capability to "skip the SIP bandwagon". Will Mr Blog get his wish?

"iBasis is a first rate partner in delivering interconnections and handling large volumes of Skype's Internet telephony terminations to the traditional PSTN network," said Niklas Zennstr?m, Skype's CEO and co-founder. "We appreciate iBasis's expertise in delivering innovative new solutions and efficiencies, and we look forward to continued joint success in expanding the consumer adoption of Internet telephony worldwide."

These distributed facilities provide support for multiple protocols and devices, network-to-network SIP authentication, and trans-coding capabilities using SIP proxies, Session Border Controllers, and trans-coding systems within the network ingress points.
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