We hope to share with you our thoughts on IT topics and issues encountered by businesses in the Bay Area.
Please feel free to contact us at 408-228-4488 or sales@netcal.com if you would like a quote for IT Support Services or a particular IT Solution.
It still amazes me how many critical IT related tasks still require a floppy disk. I came upon one of these situations when trying to install Windows 2003 Server R2 on an extra Dell Workstation I had. Of course, it wanted the drivers on A:, which didn’t exist. Of course, you could always install a disk drive… Below are instructions how to address this issue without using a disk drive. The term is slipstreaming because it injects the files just as if it was part of the original installation media.
What Is VoIP?
Voice over Internet Protocol, or VoIP, is the current technology that allows people to transmit voice signals through the internet instead of over the phone. Most people have already become acquainted with the idea of sending voice over the internet through the use of headsets or microphones, but only a few realize the unique differences between the two.
While a direct connection to a single person or a separate server allowed users to chat with each other using microphones, users still had to have telephone services in order to receive out of network calls. VoIP eliminates the obvious limitations of in network voice communication, and expands it above and beyond our expectations.
Much like an e-mail, users don’t have to pay to send or receive them. E-mails can go anywhere users have set up a mailbox, at any time. Imagine e-mail transforming from text into voice, and virtual mailboxes becoming phones. The result is a completely free, new form of voice technology capable of sending voice from an internet line and converting it into a signal anyone with a phone can receive.
Cost Advantages:
Businesses, especially smaller or medium sized companies, are always in need of more cost-effective tools and solutions. Businesses invest thousands of dollars in order to save money over a longer period of time. VoIP is a service that can potentially provide the results companies are looking for, in an even shorter amount of time. By instantly cutting costs with fewer drawbacks, VoIP has become a popular solution.
Problem: You need a plan for responding to major and minor disasters to let your company restore IT and business operations as quickly as possible.
1. Review Your Backup Strategy
2. Make Lots of Lists
3. Diagram Your Network
4. Go Wireless
5. Assign a Disaster Recovery Administrator
6. Assemble Teams
7. Create a Disaster Recovery Website
8. Test Your Recovery Plan
9. Develop a Hacking Recovery Plan
10. Make the DRP a Living Document
Backing up files can be troublesome. Speeds can reach disasterous new lows, and files tend to get corrupted along the way. It might just seem like more trouble than it’s worth, but in our experience, it makes the difference of hours and days. However, with the correct tools and information, it is possible to narrow down the problem, and even solve it. Below is a troubleshooting guide for common reasons why your server backup process may be causing errors.
1. Here is a summary of what we will be examining in order to better realize a potential problem:
o Document any noticeable problems
o When did you notice the change or error(s)?
o Have there been any changes to the main backup server, media servers, or backup clients?
o What, if anything, have you done already to troubleshoot this problem?
o Do you have any site documentation?
o What are your expectations once the problem has been ratified
2. Hardware Related Slow-down
o The speed of the disk controller and hardware errors caused by the disk drive, tape drive, disk controller, SCSI bus, or even improper cabling/termination can slow performance.
o Tape drives are incompatible with SCSI Raid Controllers.
o Fragmented disks (act of data being written on different physical locations of a disk) take much longer to back up. Not only will it affect the rate at which data is written, but it will affect your overall system performance. A solution to this is simply by defragmentation.
o The amount of available memory greatly impacts backup speed. A lack of free hard disk space is a commonly overlooked issue. This is generally due to improper file paging settings.
3. File Types and Compression
o The average file can potentially compress at a 2:1 ratio if hardware compression is used. Backup speed could potentially double if average compression is used prior.
o The total number of files on a disk, and the relative size of each file is important in calculating backup speed. The fewer large files, the faster the backup.
o Block size has an important role in compression, and thus, affects backup speed. The bigger the block size, the more capable the drive is to achieve better throughput and increased capacity. It is not recommended to increase the Block Size above the default.
4. Remote-Disk Backup
o The backup speed for a remote disk is limited by the speed of the physical connection. The rate at which a remote server’s hard disks are able to be backed up depends on the make/model of network cards, the mode/frame type configuration for the adapter, the connectivity equipment (hubs, switches, routers, and so on), and the Windows NT 4 or Windows 2000 settings.
o A commonly overlooked reason for slowdown on network backups can be the configuration of the network itself. Certain features such as “Full-Duplex” and “Auto-Detect” may not be fully supported in every environment. Setting the speed to 100Mb and duplex to half/full on the server side, and 100 MB on the switch port is the common practice. Dependent on the resulting speeds, half or full duplex will be the better solution.
5. Methods to potentially improve tape backup performance
o Make sure the tape drive is properly defined for the host system. It is common for a SCSI host to disable the adaptive cache on the drive if it is not recognized. The cache enables features like drive streaming to operate at peak performance.
o Put the tape drive on a non-Raid controller by itself.
o Make sure all settings in the controller’s Post Bios Setup Utility are correct.
o Make sure the proper driver updates have been applied for the SCSI Controllers.
o Confirm proper cabling/termination for the devices being used.
o Update the firmware on the tape drive to the latest level. In some cases, the firmware may actually require downgrading to improve performance.
o Check the tape drive and tape media statistics to see if errors occur when backups run.
o Check the Windows NT or Windows 2000 Application Event Logs for warnings/errors.
Many of the world’s largest telephone companies are committed to replacing their existing circuit switched systems with voice over IP systems. These packet switch voice over IP systems allow them to transport a significant portion of their traffic with IP. Surprisingly, many calls made over telephone company equipment are already being transported with IP.
Packet switched voice over IP systems are in principle as efficient as a synchronous circuit switched systems, but only recently have they had the potential to achieve the same level of reliability as the public switched telephone network or proprietary PBX equipment. With the invention and implementation of RTP (real time protocol) and SIP (session initiation protocol,) voice over IP has the technological base to obsolete the circuit switched public switched telephone network.
- BY Paul Mahle
Asterisk and IP Telephony / Paul Mahle
Copyright 2003, 2004 by Signate, LLC.
VoIP provides enhanced teleconferencing and remote teleworking to maximize internal productivity, save money and simplify management.
So, you are interested in implementing a VoIP system for your small business, but are unsure of the capabilities of your network. It can be broken down into 3 steps:
1. Determine how well the network is running
2. Deploy the voice over IP service
3. Verify that the service levels are working correctly.
How do you know if you current network is up to the task? What criterias determine if your network is Voice-enabled capable? What are the optimimum factors in running a smooth and clear voice over IP system?
The 3 evils of Voice over IP networks.
1. Delay (minimum of 150ms, use Cisco RTPC + LFI)
This is the time it takes voice to travel from one point to another on the network. It can be measured in one direction or for the entire round trip. The calculations of delay usually involves Network Time Protocol (NTP) and clock synchronization and reference clocks.
2. Jitter (the optimal jitter buffer should fit the network’s differential delay, Cisco’s LFI)
This is the variation in delay over time from point to point. The higher the variation, the more degraded the call quality will be. The amount of tolerable jitter on the network is affected by the depth of jitter buffer on the network equipment in the voice path. When more jitter buffer is available, the network is more able to reduce the negative effects of a broad variation. Unfortunately, a buffer can also be too big. This would increase the overall gap between packets.
3. Packet Loss (less than 2.5-5%, use QoS that differentiates between data and voice packets.)
Packet loss refers to the packets of data that are dropped by the network to manage congestion. Data applications are very tolerant to packet loss, as they are generally not time sensitive and can retransmit the packets that were dropped. Dropped packets in a VoIP network appear as noise in the conversation and may require the speaker to repeat or retype the last word or sentence, which is clearly undesirable.