CoNetrix

Blog: AT&T

One of our Technology customers recently migrated to a new AT&T WAN offering called AT&T Switched Ethernet – Network on Demand (ASE NoD). This is the most recent evolution of their metro Ethernet service with the addition of long-distance layer 2 connections.

What makes this "network on demand" is the ability to change bandwidth as needed through a web portal up to the physical Ethernet hand-off limit, typically 10Mb/s, 100mb/s, or 1Gb/s. The default rate for each of this customer's location was set to 20, 50, or 100Mb/s.

Since this is a relatively new product we had several Gotcha's in the implementation:

  • The customer ordered 1Gb/s hand-offs delivered over single-mode fiber. This required new optics or media converters for sites with routers that had only UTP connections. We later learned that AT&T can provide the 1Gb/s hand-off using multi-mode fiber or UTP connections. Changing from single-mode would have required modifying the order and delaying the implementation, so we stayed with what was ordered.
  • The actual bandwidth for billing is based on the Committed Information Data (CID) rate. Initially this was set to 20Mb/s for most sites, which matched the price quoted by AT&T. We wanted to increase the bandwidth for one location but the portal did not allow any changes above the default CID. After several calls to AT&T we discovered there was a internal maximum set at 20Mb/s.  We had them change the maximum to the hand-off speed of 1Gb/s to fix this problem.
  • After fixing the issue above, the Ethernet Virtual Channel (EVC) for each site changed to 1Mb/s, but thankfully only in the portal. The actual EVC did not change. It took another series of calls with AT&T to fix this issue.
Networking, AT&T, Switched Ethernet,
 

I had to troubleshoot a point to point T1 circuit that was down.  The circuit is joined between two different carriers.  One side of the circuit was Verizon, and the other side was AT&T.  We weren’t sure who to call originally, so both of the carriers were called to troubleshoot the circuit.

While tests were being done, I was able to go onsite and tell right off the smartjack had no lights on it at all.  AT&T local technician was eventually dispatched to move the connection over to a spare smartjack onsite.  After everything was moved, we rebooted the routers at both ends, but the circuit was still dead. [more]

The technician finally decided to try sending a loopback clear signal down the entire line stating that “It appeared that there was still a software loopback somewhere on the line that wasn’t removed after testing.”  After he sent the signal down the line, we rebooted the routers and the circuit came back up.

This is something handy we can ask the onsite technicians to look for in the case where everything looks like it should be working but isn’t.

Networking, AT&T, Verizon, T1,
 

A CPA client of ours runs a proprietary audit software called ProSystems Engagement that allows auditors to sync their data to each other. The auditors were having trouble syncing the data between their systems. The customer has some older Lenovo (T-42 and T-60/61) laptops and some new Lenovo W700 laptops. Their older laptops could sync with each other and their new laptops could sync to the old laptops. But neither could sync to the new laptops. I worked with the software vendor and ran about every query and test they had trying to pinpoint the cause. But was unable to determine why the new laptops could not be synced too. [more]

Luckily, the customer had order a new W-700 that I needed to setup. So using it as a test I began setting up the laptop as per their checklist. At every stage I tested the sync process. The last thing to be installed was the AT&T Communication management software for their 3G modems. (which they need) After completing the install Prosystems sync would not work. I uninstalled the AT&T software and sync worked. I reinstalled and it broke. I looked through the software settings and found that it installs a ByteMobile Acceleration program. I had previously, on another system, deselect the option to use the acceleration program and it still would not sync. I choose to uninstalled just the ByteMobile software and the sync worked, as well as the AT&T software and 3G modem.

The Bytemobile acceleration client is used to increased data reduction and speed-up the download process. It offers bidirectional optimization for dramatically reduced traffic on the uplink. It intercepts and optimizes all TCP network traffic generated from and received by the device. The software supports protocol-agnostic compression, lossy and lossless image file reduction, and delta compression techniques to ensure that the same data is not downloaded to the client repeatedly. It claims to preserves interoperability with third-party Windows applications such as internet security, personal firewall and VPN software. Client applications such as web browsers and remote applications such as web servers are suppose to be unaware of the application between them and operate as if communicating directly with each other. Since the sync process compare and transfers the same data throughout the process the acceleration client was causing the sync to fail.

Networking, 3G, Lenova, AT&T,
 

Over the past several days AT&T customers have reported a drastic increase in the number of non-spam messages being rejected by AT&T SPAM filters.  [more]

The sender may receive a message such as "An error occurred while trying to deliver this message to the recipient's e-mail address.  The following organization rejected your message: att.net", and the receiver might view a log with a message similar to "550 Error. Blocked for abuse".  However, many of the messages are from legitimate users or companies.

To get the sender off of the "SPAM" list, you can either call AT&T or submit appropriate information into the form on the following website provided by AT&T, http://worldnet.att.net/general-info/mail_info/block_admin.html

To read more, visit http://www.techdirt.com/articles/20080325/002950640.shtml or http://www.theregister.co.uk/2008/03/24/aggressive_att_spam_filters/

General, Networking, SPAM, Filter, AT&T,