By the time you read this, Cisco will have begun shipping its new "Unified Communications System," driven by the Cisco Unified CallManager 5.0. The package represents two years' work, and a major migratory step for Cisco IP telephony relevant products/services from Cisco. First, call control is now Linux-based. But even more significantly, Cisco has seamlessly embedded SIP, natively, right alongside the vendor's proprietary call control. Testing by Miercom has shown that Cisco delivers as good performance, security, and virtually all the same features, over SIP that it has via its proprietary "Skinny" protocol.

It is a bold move. Indeed, as far as support for SIP-based IP telephony, it lets Cisco leapfrog many of its competitors, whose customers still must buy separate, add-on subsystems to get SIP device and phone support.

Early last month, Miercom's lab team conducted the first independent hands-on review of a late-beta version of CallManager 5.0, codenamed "SeaDragon." It is the flagship offering in Cisco's new SIP-supporting IP-telephony product portfolio.

Our testing found that the interworking of SIP and Cisco-proprietary phones on a CallManager 5.0 system is effectively transparent -- the few minor differences we noted between SIP and Skinny calls would be imperceptible to users, and Cisco says it's working to eliminate any lingering user-interface differences. We confirmed that Cisco delivers the same fast call set-up, connection and voice quality, and all the security, failover and survivability features for the SIP environment that it had delivered via its proprietary "Skinny" -- including for SIP-to-Skinny calls.

Practically all of Cisco's current IP phones can run SIP -- it is an alternative phone firmware download. However, for older Cisco phones, the SIP feature set is reduced. Due to the smooth and seamless interworking of Cisco's Skinny and SIP phones, it doesn't make much sense to convert existing, older Skinny phones over to SIP, since you'd suffer a net loss of features.

Users get optimal performance and maximum SIP functionality by running SIP on Cisco's latest IP hard phones, which the vendor developed with its forthcoming SIP and CallManager 5.0 environment in mind. Because SIP involves heavy endpoint processing (compared to most proprietary protocols, where much of the processing is done on the call controller), Cisco had to come up with a beefed up line of phones for SIP.

Cisco's new IP-phone series, optimized for SIP, includes the 7971, 7961, 7941 and 7911. These cost about $50 each more than their pre-SIP predecessors, but they offer enhancements including higher-resolution displays, in addition to greater processing power for SIP. These same phones run Skinny, too.

TABLE 1 New Cisco SIP-Supporting Call-Control Packages

Transition To SIP, Linux

The other major element to the CallManager 5.0 announcement is the new operating system. Cisco took the Microsoft Windows 2000-based CallManager, currently release 4.1(3), and—over the last two years—ported every bit of the code over to run on Linux. Then it built-in SIP call control, in the form of a back-to back SIP user agent, and mapped as many Skinny features to SIP standards and drafts as it reasonably could. Cisco has implemented more than 20 of the core and key new SIP RFCs, plus a halfdozen leading SIP Internet Drafts.

In terms of features, we believe Cisco’s latest SIP implementation supports over 90 percent of the features that Skinny phone users get. Given the state of SIP advanced-features specifications, not all of these would necessarily interoperate with other vendors’ SIP implementations. Cisco delivers CallManager 5.0 already installed on Linux, on the vendor’s MCS series of servers. But it also includes all the CDs and procedures to
completely upgrade existing Windows based v4.1 CallManager servers to 5.0 on Linux. This process takes some time, especially to back up and move off the configuration files, which then are imported back into the Linux-based version— but it does work. Our testers spent 12 hours doing the upgrade, but when they finished, it worked as advertised— and you don’t need to be a Linux/Unix guru to do it.

All CallManagers in an operating “cluster”—that is, part of the same IPPBX “system”—need to be running the same CallManager version. So, to deploy SIP, all CallManagers in an enterprise network have to be running, or upgraded to, version 5.0 on Linux. There’s no direct charge to upgrade existing Windows servers to Linux, but
you do need to be on a Cisco software service contract to get the full upgrade package.

Linux is widely regarded as generally more secure, and often better performing, than Windows as an IP-PBX callcontrol platform. Cisco officially says only that its new Linux version simply offers users the choice. Indeed, Cisco says it is not dead-ending the Windows 2000-based CallManager 4.1. The vendor says new versions of the Windows based version are in the works and that SIP will be added to the Windows version within the next 12 months. At that time, the Windows and Linux versions will offer the same protocol support and functionality.

What’s New?

Existing CallManager customers may not be sufficiently motivated by SIP support alone to upgrade to the new 5.0 on Linux. As it turns out, though, the new system delivers a number of other new capabilities and features. This includes “presence,” which shows all CallManager users—whether SIP or Skinny—the real-time phone status of others on the same IP-PBX system. The basic Call-Manager 5.0 provides rudimentary presence capabilities, and more advanced functionality is available with the new Cisco Unified Presence Server (described below).

Table 2 summarizes the key new capabilities of what Cisco terms its “unified communications system,” most of
which the Miercom test team has tested and verified. These new features include support for various new and enhanced Cisco applications, including:

• Unified Personal Communicator—A slick new SIP-based client for PC and Mac users, which offers ready access to voice mail, presence-enabled directory, and even desktop video.

• New SIP-enabled versions of MeetingPlace Express, IP Contact Center (IPCC) Express, Unity Connection and MobilityManager.

• The new Cisco Unified Presence Server, which delivers presence to the Unified Personal Communicator, and alsoenables applications such as the IP Phone Messenger, for message exchange via phone displays.

Being SIP standards-based, CallManager 5.0 also naturally supports the mushrooming proliferation of third-party SIP phones and devices. The Miercom test team verified operation of the RIM BlackBerry 7270, running SIP over802.11b WiFi, via the new CallManager.

At press time, Cisco was still finalizing its formal interoperability-certification program, which it says will be performed by multiple outside labs. But Cisco makes clear that it welcomes users to go ahead and connect third-party SIP devices. These devices won’t be formally supported by Cisco until tested and certified, the vendor says, adding that basic SIP features and functions have been found to work just fine on third party phones its has informally tried.

Key new benefits and capabilities of Cisco’s CallManager 5.0:

• Concurrent support of SIP and Skinny phones, and seamless interoperability between the two.

• New SIP-enabled and SIP-based applications are now offered (including Unified Personal Communicator)—with video, click-to-dial; and Unity Connection (featuring voice recognition, and Personal Assistant-type call handling).

• Support for third-party SIP endpoints.

• On-hook/off-hook presence is added, for all phones. A new Presence server is also now offered, which offloads presence processing from the CallManager.

• Call-control management is now all consolidated via the same Web interface, unlike inthe Windows environment.
  

• An optional technique for VOIP QOS over the WAN—RSVP (the resource reservation protocol) is now supported.

• All existing connectivity and applications continue to work without change.

• New SIP trunking to applications including MeetingPlace Conferencing, Unity voice mail, and IP Contact Center.

• SIP is now also supported on Cisco gateways, and can be mixed and matched withcurrent gateway protocol support (including H.323 and MGCP).

Conclusion

CallManager 5.0 is a bold move on Cisco’s part. With it, Cisco has put SIP on an even footing with its proprietary protocol—a strategic move that some of its major competitors have so far avoided, but will probably now need to rethink.

Cisco expresses confidence that it offers customers more value with its new SIP phones than they can get with lowcost, third-party, SIP-phone alternatives. That is certainly the case as far as provisioning and management, two areas still very unsettled in SIP standards circles.

Will Cisco Unified CallManager 5.0 emerge as a leading SIP-only IP-PBX?
That is something customers will decide. One thing is clear: Cisco deserves kudos for offering customers the choice.


Ed Mier is founder of Miercom, a
network consultancy in East Windsor, NJ.
He can be reached at: This email address is being protected from spam bots, you need Javascript enabled to view it
or 609/490-0200. Robert Tarpley is
Senior Engineer, and can be reached at
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