Daily Network Monitor

By Greg Paul

Solera Networks, Inc., has introduced a new hardware product; for managing packet recorders distributed throughout a network. Here is an excerpted version of the press release that announced the product.

Control Center software for its packet recorder appliances. This initial release of the web-based interface software allows network administrators and security analysts to:

- Select, start, and stop physical capture, virtual replay, and/or regeneration processes
- Create and apply filters to the network data stream before capture or upon replay
- View graphical and numerical status of key system metrics
- Navigate and download PCAP files or PCAP header files of stored network data
- Create custom PCAP files selected by date-time or file size from the stored data
- Issue console commands to the appliance
- Add and manage users and user rights

Based on proprietary system software and the DS infinite storage file system, Solera Networks DS appliances achieve over 2X the sustainable capture and stream to disk rates of competitive products and can directly address disk storage in excess of 240 TB.

The DS series appliances capture LAN and WAN traffic of all types including T1, E1, digital, T3, DS3, E3, VoIP, HSSI, and all other packetized transport protocols. Up to 10 capture or regeneration ports can be configured on each device with 10/100, GigE, 10GbE, or Fiber Channel adapters.”

Popularity: 1% [?]

By Greg Paul

WINDSOR, Ontario, Dec. 21 /PRNewswire/ — Network monitoring appliance vendor Netmon Inc. is pleased to announce a distribution partnership with PCMall, Inc., a national provider of technology solutions for business, government and educational institutions.

Under the new arrangement, PCMall will provide Netmon products to its large base of corporate, government and institutional customers through its various web properties, which include www.pcmall.com, www.pcmallgov.com, and www.onsale.com.

“Our appliances provide network administrators with a comprehensive view of their critical infrastructure,” according to Jason Pomerleau, Product Manager for Netmon Inc, “Imagine adding hundreds of pairs of eyes to your network, each working 24 hours a day to monitor key performance and operational metrics.” A built-in email and pager alert system is designed to keep administrators informed of important events which require attention or intervention.

Describing the new partnership as a “win-win proposition for all parties” Netmon President Eric Lamoureux states, “PCMall customers will now be able to purchase our products through a vendor they already know and trust, and we in turn are able to make our products accessible to a larger audience.”

Popularity: 1% [?]

By Greg Paul

Germany’s Siemens has set a speed record for electrical processing of data through a fiber-optic cable, it said Wednesday, opening the possibility of cheaper Internet and data networks.

Siemens said in a statement that it had processed data using exclusively electrical means at 107 gigabits per second–roughly two full DVDs per second–and sent it over a single optical fiber channel in a 100-mile U.S. network, the first time outside of a laboratory.

Online games, music and video downloads are generating increasing amounts of Internet traffic, creating a need for ever-faster and affordable transmission.

The test, two-and-a-half times faster than a previous maximum transmission performance per channel, was done in cooperation with Germany’s Micram Microelectronic, the Fraunhofer Institute for Telecommunications and the Netherlands’ Eindhoven University of Technology.

Siemens said the advantage of its method of using electrical processing only was that it removed the need to split signals into multiple signals of lower data rates to avoid bottlenecks. Such bottlenecks make transmissions slower and more expensive.

“Such a system would be particularly interesting for the future 100-Gigabit Ethernet, on which the telecommunication providers are currently working,” Siemens said.

See the whole story here.

Popularity: 1% [?]

By Greg Paul

Solera Networks, Inc., has introduced a new hardware product; for managing packet recorders distributed throughout a network. Here is an excerpted version of the press release that announced the product.

Control Center software for its packet recorder appliances. This initial release of the web-based interface software allows network administrators and security analysts to:

- Select, start, and stop physical capture, virtual replay, and/or regeneration processes
- Create and apply filters to the network data stream before capture or upon replay
- View graphical and numerical status of key system metrics
- Navigate and download PCAP files or PCAP header files of stored network data
- Create custom PCAP files selected by date-time or file size from the stored data
- Issue console commands to the appliance
- Add and manage users and user rights

Based on proprietary system software and the DS infinite storage file system, Solera Networks DS appliances achieve over 2X the sustainable capture and stream to disk rates of competitive products and can directly address disk storage in excess of 240 TB.

The DS series appliances capture LAN and WAN traffic of all types including T1, E1, digital, T3, DS3, E3, VoIP, HSSI, and all other packetized transport protocols. Up to 10 capture or regeneration ports can be configured on each device with 10/100, GigE, 10GbE, or Fiber Channel adapters.”

Popularity: 1% [?]

By Greg Paul

Saw this great blog posting on ZDNet recently…

E-Way Technology Systems is a company from Taiwan that is selling a tiny 200 MHz x86-compatible fanless mini PC with 128 MB RAM, Fast Ethernet, and front loading compact flash slot for $99 at single quantities! Of course this wouldn’t be very useful as a full desktop computer, but it is the perfect low-power fanless zero-moving-part silent appliance at an unbelievably low price. Here are some of the things you can do with this hundred dollar box.

Citrix or Terminal Server thin client (you’ll need to add keyboard, mouse, and a display). By the time you add those things, you might be up to $300 but it’s multiples cheaper than other thin clients.
Small office or home office Asterisk PBX to support a couple of phones and voice mail boxes (So long as you don’t try to transcode anything).
Change to a board with no video and audio but with multiple Ethernet ports and this can become a killer IPCop appliance.
The front loading CF (Compact Flash) slot is super convenient for firmware upgrades since you can easily extract the CF card and flash the image from a regular computer.
It could probably serve as a Linux Wi-Fi appliance as well with an
But this hundred dollar unit is a little under powered and I couldn’t help but wonder if there is a more powerful solution. I went to E-Way’s website and found this 800 MHz fanless mini-ITX system with 256 MB RAM for a mere $199 at single quantities ($150 at 300 units). But even at $199, you can’t even build a mini-ITX system this cheap in component costs alone! Mini-ITX components are usually very expensive.

It doesn’t have the front loading CF slot but it has a PXE boot ROM and very good performance characteristics. This unit can use CF or hard drives in the thicker model. This would probably make the perfect PBX system if it was coupled with something like the Astrabank-8 which is a USB device that provides 8 analog phone ports for analog phones or fax machines. The performance and hard drive would allow it to handle many more users and voice mail boxes.

It could probably handle DVD playback with ease since it has MPEG 2 acceleration though I doubt if it will handle HD video play back. As a media PC, it has limitations because it lacks HD component out and only has a DB-15 VGA port and no DVI. But it would probably make a killer car PC since it doesn’t use a lot of power (no more than 20 watts) and you could hook up an LCD panel to it. It’s small enough to easily mount under the car seat. As a firewall appliance, it would need to have more Ethernet ports though I’m not sure if that’s an option with this mini chassis or not. E-Way does sell 3 and 4 port fanless systems that are perfect for the firewall appliance which may even be fast enough to do in-line virus scanning for a small number of users.

Popularity: unranked [?]

By Greg Paul

This story appeared in Network World here.

“We are used to breaking products in lab testing, but this time we broke 802.11 itself. Our tests uncovered a design flaw in the Wi-Fi protocol that affects performance testing, not just for current 802.11a/g products, but possibly in upcoming 802.11n gear as well. As a result of our tests, an IEEE committee heard a proposal to recognize and fix the design flaw.

It’s a common misperception that Wi-Fi is an inherently “lossy” medium. Wi-Fi is highly vulnerable to signal errors, but it compensates with built-in error checking and retransmission mechanisms. Even a huge error rate (say, 10% of all packets, the maximum allowed in 802.11) should still result in zero loss, because packet errors are retransmitted.
That’s the theory. In practice, we found a deficiency in an 802.11 packet header that can lead to packet loss.

The physical layer convergence procedure (PLCP) header carries key information about each packet, such as its length and transmission rate. While the rest of an 802.11 packet has excellent error protection because of a 32-bit CRC field, the PLCP header has only a single bit for error checking, and that is nowhere near enough to protect against corruption.

Weak PLCP error checking can fool an 802.11 receiver into believing that it never received packets, even after a transmitter goes through multiple retry attempts.

For example, suppose an 802.11g transmitter sends a 100-byte packet at 54Mbps, and that channel noise corrupts the PLCP header. The corrupted header can convey bogus values, such as telling the receiver the packet is 4,095 bytes long and is being sent at 6Mbps.

An uncorrupted packet would take just 36 microsec to transmit, but in this case the corrupted PLCP header will cause the receiver to keep listening for the packet for 5,484 microsec. The receiver is literally off the air for that long period, causing it to miss multiple retry attempts and give up on the packet as lost.

This perceived loss makes it harder to get an accurate read on device performance. It’s standard practice in throughput and latency tests to tolerate zero dropped packets. Because weak error checking in the PLCP header introduces packet loss, lower throughput rates are a likely result.

Weak error handling also can affect roaming tests. If a receiver misses an Extensible Authentication Protocol handshake packet during a roaming event, it can take 30 seconds before the RADIUS handshake begins again. We saw some 30-second roaming times in our tests because of this issue.

The probability of PLCP corruption with short packets and high rates is around one in 1,000. Because performance tests inevitably involve far more than 1,000 packets, results easily can be skewed downward by corrupted PLCP headers.

We compensated for this issue by setting an acceptable loss threshold of 0.1% in our throughput tests. We’re not crazy about allowing loss in throughput tests. It’s a violation of RFCs 1242 and 2544, and it’s a common dodge used by vendors of poorly performing products.

In the absence of a better solution, however, we opted for the acceptable packet loss to mask any instances of PLCP header corruption.

While there’s no chance of changing the 802.11a/g standard because of backward compatibility issues, it’s not too late for the IEEE to correct this design flaw in the forthcoming 802.11n standard. The IEEE recently heard a proposal to address the issue uncovered in these tests.

At the IEEE 802.11 meeting in Melbourne in September, test equipment maker VeriWave and Wi-Fi switch vendor Aruba Wireless Networks jointly outlined the problem and described its implications for performance testing. The current 802.11n draft uses the same PLCP structure as 802.11a/g when operating in mixed mode (with 802.11b/g clients present). The presenters recommended stronger error protection for 802.11n mixed-mode operation, as well as warning language in the forthcoming 802.11.2 standards to alert testers to the design flaw.

An obvious question is why this phenomenon hasn’t been seen before. The answer has much to do with the relatively crude state of Wi-Fi performance testing. Besides the perception that “it’s just wireless,” previous tests haven’t offered enough packets at high enough rates, and closely analyzed the results, to understand that the current 802.11 protocol is itself an impediment to improved performance.”

Popularity: 3% [?]