The ECG staff technical blog.
The performance of the Cisco Catalyst 3750 is a funny thing. Software-based routing, called process switching, can only switch 2500-3000 packets per second[1]. But the box itself is rated at 6.5 million packets per second[2], using hardware-based switching. That's a huge disparity, larger than on Cisco's official "router" products. For example, the Cisco 2821 can process-switch 75,000 pps, and...
I'm no expert on telephone company management, nor the iPhone itself, nor the internal AT&T wireless-side organization. But I have been around numerous telephone companies, and have some ideas about AT&T and the iPhone.
At the time of this post, lots of people are complaining of trouble activating the iPhone. My guesses about some sources of trouble:
The iPhone doesn't have an externa...
The IETF SIP Working Group has a sub-group working on SIP Location Conveyance. The current draft isdraft-ietf-sip-location-conveyance
This is proposed as a tool to enable SIP endpoints (such as SIP phones or ATAs) or their proxy upstream to convey the calling party's location to the called party. The imagined applications are:
Calling an emergency number, like 911, so the first-responders know...
Consensus is growing among some system implementors that Verizon's patents for calling to PSTN and VoIP endpoints is tightly coupled to "direct media". This article discusses the three claims on which Vonage was found infringing and how it relates to other hosted VoIP carriers, like those using MetaSwitch, Sylantro, or BroadSoft.
US Patent 6,104,711, Claim 20 talks about making calls directly t...
Verizon sued Vonage in case 1:06-cv-00682-CMH-BRP in the US District Court of the Eastern Virgina region. Verizon has won, for now. As people who make VoIP work, the engineers and operators of VoIP systems need some actual useful information to work with to build networks that observe Verizon's patents. This posting is just an attempt to collect some of that info in a useful place.
The web i...
VON trade show: the no-show list
San Jose, CA -- The VON spring 2007 trade-show this year was notable for who was absent. Among the non-attenders: Cisco, Lucent, and Nortel. Sonus didn't have a booth, but they rented some meeting rooms.
To be precise, Cisco was present in the logos of some literature in the Linksys booth, but the extremely popular Cisco SIP phones and AS5400 gateways were not ...
San Jose, CA -- I had wondered in the past whether GS did any VoIP engineering or support, and I got my answer yesterday at VON. I learned about IBM Global Services' Support for VoIP Systems.
The Global Services VoIP support offering that I learned about is focused on supporting technical staff at enterprises. (NB: "Enterprise" is jargon for for any customer that's not a government, a carrie...
Voice over IP is obviously big seller these days. Everybody wants to do it. But is VoIP really there yet? I mean, can you depend on it the way you rely on traditional telephony? There are some simple reasons to expect not:
The systems are all very new. Joel Spolsky makes strong points that it takes about ten years for software to mature to being truly useful.
The feature set is very ric...
Mark Lindsey