Email is a very useful tool. Like any tool, there are right ways to use it, and wrong ways to use it. There are a few common etiquette mistakes that lots of people make using email, and I’m going to talk about one of the biggest: How to properly address email to a group of people. Continue reading
I have struggled with this issue for a while on a large deployment (6 servers hosting ~175 extensions). An extension would complete a call, and the SIP channel on the extension side would fail to release when the call terminated, resulting in the extension appearing to be busy to the server. All calls go straight to voicemail. Calls can be initiated just fine, but I could not find a resolution for releasing the channel short of restarting the server, which is obviously not the desired method of resolution. This issues is addressed in the Asterisk ticket here: https://issues.asterisk.org/jira/browse/ASTERISK-19455, but no short-term resolution to the immediate problem of the channel that won’t die.
SO… Today when this issue happened, I stuck with it longer that I had in the past, experimenting with trying to stop the channel. Here’s how I was able to release the extension without a complete reboot of the server. Continue reading
In 2007, the Logan County Emergency Services Telephone Board secured a grant to upgrade and relocate a thirty plus year old communications room. I was fortunate to be a part of the team that designed and implemented the new communications room and equipment. In particular, the role I played, and continue to play, is the Information Technology glue that ties everything together in the room. We are all very proud of what we have accomplished, and Logan Dispatch is known state wide for creating a room that is a quiet, efficient and pleasant space in which to do a very difficult job.
A few important pieces that we put together to make this environment possible, were the room itself, including the redesign of the space, excluding any computers from actually being in the room itself, and combining the 4 (5 on position 3) computers in such a way that one keyboard and mouse control them all seamlessly with no switching or swapping of input devices.
More information with details of how we achieved all this to come soon.
In struggling with time synchronization under Windows 2008 R2, I came across an issue that had me stumped for a bit. I have a client with Windows 2008 R2 Standard running in a virtual machine in Hyper-v. I have configured it to sync time from pool.ntp.org using the w32tm as instructed here, here and here.
The Hyper-v host is getting it’s time reference from the PDC that it is hosting as well. When the client complained that the time was off by something like 8 minutes, I began checking into the issue. When running
w32tm /stripchart /computer: target /samples: n /dataonly
I was getting back sporadic 0x800705b4 errors mixed in with the reports that my server was 378.023845629 (or so) seconds off. I didn’t see reference to that anywhere I Googled. for it to error every time? Sure. Mixed in the same results with successful connections? Not one. I checked the firewall settings anyway. Also, forcing sync had no effect. The clock was still off by three hundred and seventy whatever seconds.
Finally I found my problem. In integration services, time sync to the host is one of the options. So I was syncing my host to my PCD which was trying to sync pool.ntp.org, but being overridden by the integration services and syncing to the host.
Moral? Virtual machine settings –> Management –> Integration Services –> Time Synchronization? Uncheck it.
It seemed like a good idea at the time.
Talking to Aastra tech support about a deployment issue with the 6757i, they requested a wireshark capture of the phone as it booted. Simple, right? I’ve used wireshark a lot through the years, and luckily for me, most of my use in the past has involved a linux router that I could run it on directly. I didn’t have to worry much about switches and taps. Not that I haven’t done that, too, just not for a while. Namely not before Gigabit Ethernet hit the scene.
There are articles by the ton about building a passive network tap, and I’ve even done it before, though it was about 8 or 10 years ago. Here are a few that I referenced:
In the interest of making the endpoint deployment easier, we are working toward this model:
- Unbox, assemble and install the phone.
- Phone’s first boot gets its IP from the data network VLAN, and gets config from TFTP assigning it to the appropriate voice VLAN and rebooting.
- Phone now boots into voice VLAN and gets IP and config server from the voice space. The TFTP config here kicks off the Aastra process that requests the extension and password and configures the phone.
Passwords can be a real pain.
We computer geeks really do understand that. It just comes down to the fact that we’re not operating locally anymore, we’re operating globally. Maybe you live in a great community, and you feel safe and comfortable enough in your community to sleep at night in an unlocked house. That’s great. For you, passwords probably seem like a lot of bother for nothing. The problem is that all of our virtual, online “doors” exist in dark corners where anyone in the world within reach of a computer can rattle the doorknob. And they do. You might be shocked how often. It’s hundreds of times. Not hundreds of times in a year, or even a month, but in a day. Sometimes even in the course of a few minutes. Continue reading
Deploying a multi-building, multi-campus VoIP telephone system using Asterisk.
Our university campus is working from a phones system older than most of the students attending here. There is little functionality (at least accessible to the end users) beyond the ability to answer calls and get voicemail at the phone. We’re moving toward a system that will allow us to take advantage of the technology available to us to both increase the utility of our campus telephony, and also greatly reduce the monthly expenditure on traditional PSTN connectivity. I intend to document most of the journey here in the hopes that it will prove useful to someone else with an equally challenging environment and set of goals. Continue reading