You don't need Gigabit Ethernet to support VoIP, but if you upgrade to GigE for other reasonsto support high-bit rate applications such as video or to accommodate creeping inflation in network capacity requirementsyou do need to think about the implications for IP telephony.
Broadcom, a leading provider of silicon to VoIP equipment manufacturers, thought through the implications and earlier this year introduced the first IP phone chip with an integrated Gigabit Ethernet switch. The new chip design also incorporates a raft of new features and capabilities, including significantly improved security and increased processing capacity.
The BCM1103 is a single chip IP phone solution that comes with the company's PhonExchange software suite. Hardware and software together provide all the core IP phone functions. Phone manufacturers only need to tack on differentiating, value-added features. The chip costs $25 in quantities of 10,000 or more.
But why do you need a GigE switch in an IP phone if VoIP doesn't require that kind of throughput?
In most offices, there is one Ethernet jack per desk, and in most IP telephony implementations, the IP phone set sits between the jack and the PC to make it easier to implement quality of service (QoS) functionality. If the phone incorporates only a 10/100 switch to route traffic to the PC, you have a problem.
"We all know that Gigabit throughput is not required for IP telephony," says Bill Boora, a product marketing manager at Broadcom responsible for the IP phone space. "So the primary need here is to be able to provide full Gigabit throughput to a PC daisy chained off the IP phone. Putting the switch in the phone is a way of future-proofing it."
New silicon empire?
In most hardware markets, silicon vendors are the anonymous power behind the throne. Broadcom, however, clearly aspires to the industry clout and brand name recognition of an Intel, and may be achieving it. The company also makes chip level products for wireless IP phones, residential broadband gateways and terminal adapters and carrier/enterprise-class VoIP gateways.
The fact that it was first with a Gigabit Ethernet phone chip in January and that no other silicon vendor has followed suit yet is one more indication of the company's growing dominance, Boora says.
Until three years ago, Texas Instruments (TI) held the lion's share of the market, but in 2000, both TI and Broadcom introduced single-chip 10/100 Mbps IP phone solutions. "To put it politically correctly," says Boora, "our chip worked. TI had some issues with theirs."
The result is that today, according to Broadcom's analysis, eight of the top ten and four of the top five IP phone vendors are using Broadcom chips. Six of the eight are using Broadcom in all their models. The customers the company is allowed to talk about include Avaya, NEC, Toshiba, and Inter-Tel. That dominance should continue with the new chip.
"Multiple tier 1 customers" are currently designing products around the BCM1103, Boora says. Broadcom shipped the first customer samples last October. Volume shipments of finished product from phone vendors should begin in early fourth quarter, he says.
That migration to Gigabit Ethernet, meanwhile, is already well advanced. Broadcom cites forecasts from market research firm Dell'Oro Group showing Gigabit Ethernet port shipments at 31.5 million in 2004, projected to more than 53 million by the end of 2005, and growing to around 213 million by 2008.
Not that 10/100 Mbps Ethernet IP phones cannot work in a Gigabit Ethernet environment. The alternative to a phone with a built-in switch is to introduce an external multi-speed switch device that takes Gigabit Ethernet in and routes data at full GigE data rates to the PC and voice packets to the phone at 10/100 Mbps. Broadcom argues fairly convincingly that a phone with an integrated switch is a more cost effective solution.
More powerful, more secure, more versatile
The new Broadcom chip also offers more than just Gigabit Ethernet switching. Most important are the improvements in security. With earlier generation products, the IP phone's unique hardware ID could be read using debugging tools and then burned into another phone to gain illegal access to a system. With the BCM1103 chip, the hardware ID cannot be read without destroying the phone.
Encryption and decryption of voice packets and signaling information is now handled by a separate processor, freeing up the main RISC processor for application processing. The RISC processor in the new chip has also been beefed upit runs at 275 MHz rather than the 150 Mhz of earlier generation chips. There's a separate DSP (digital signal processing) chip as well that provides three-way conferencing and full-duplex speaker phone functions.
"Because we've freed up more processing power, it gives developers the ability to add richer features," Boora explains. "They might have an enhanced Web browser on the phone, or maybe they use Windows CE to do PC applications, to run Outlook, for example. They're no longer limited to just basic features."
Having all of these functionsdedicated encryption-decryption engine, DSP, application processing, and USB on one chipreduces the need for additional silicon products to build the phone, and that helps make the BCM1103 a more cost effective solution, Boora saysalthough its cost effectiveness will depend on the features developers build in to their phones.
"If they use this chip and want to use all or a lot of the features, then it will provide a lower system solution cost [than earlier generation chips]," he says. "As you increase the feature set of phone, then the costs will come down."
That being said, Broadcom has provided enough flexibility in the design that developers can also use the chip in 10/100 Mbps phones. Why would they want to do that? Two reasons, Boora says. If they're building a new line of phones and want most to be GigE but a couple to be 10/100, they can use the BCM1103 in all and maintain uniformity and consistency of features and reduce design-related development costs. Developers can also use the chip in transitional products that are field upgradeable to Gigabit Ethernet by inserting a daughter card.
What does all this mean to enterprise IT and telecom managers? If you've already deployed either Gigabit Ethernet or VoIP and are now contemplating deploying the other, how will you handle switching between phones and PCs at the desktop?
The options now are 1) invest in external dual-mode switches, 2) use existing phones with integrated 10/100 Mbps switches but forego full GigE throughput to the PC or 3) pull cable for a second drop at each desktop. Or you can wait until new GigE phones based on the Broadcom chip are available.