This is the email I got from allegiance, though they only started a few days ago from what I can see:
Dear Valued Customer:
Under the terms of a purchase agreement, XO Communications (XO™) agreed to
purchase substantially all of the assets of Allegiance Telecom, Inc. In
early April 2004, Allegiance and XO closed this sale transaction into
escrow." On the same date, XO and Allegiance entered into an operating
agreement that allows XO to manage the Allegiance assets that XO is
acquiring until the final close of the acquisition, subject to Allegiance's
approval. One of the initial projects is IP Network integration.
In an ongoing effort to provide our customers with premiere Internet Access
products, the XO/Allegiance Team will be making numerous IP Network
modifications aimed at improving the IP connectivity our customers receive.
These IP Network modifications will occur over the next four months, and
this letter addresses the first step in the process. The final outcome of
these modifications will result in a single, but larger, integrated IP
What exactly will happen?
Between May 19th and June 1st, 2004, all Allegiance IP traffic will prefer
XO routes via interconnections at peering locations. Shortly thereafter,
all Allegiance peering connections will be turned down and all Allegiance IP
customers will peer via XO (AS2828.) All Allegiance Internet Access
customers will temporarily see an additional AS hop from their router to the
final IP destination.
Why is this IP Network modification necessary?
Turning down Allegiance’s peering connections is the first in a series of
steps that must be taken as the XO/Allegiance Team works to integrate the
two networks onto a single, high-capacity, more efficient IP Network. In
the end, all Allegiance and XO IP customers will reside on a single IP
Network, AS2828, which will allow the combined company to more efficiently
and effectively manage, monitor, and troubleshoot all IP customers.
Who is impacted?
All Allegiance Internet Access customers will be minimally impacted by the
peering modification. Customers who run BGP with Allegiance may see traffic
shifts and therefore may decide to update their existing BGP configurations.
BGP customers will initially notice a longer AS Path length, as AS2828 (XO)
will be inserted into all routes.
What action do I need to take?
No action is required for BGP customers. However, the longer AS path may
impact how your BGP session decides on certain routes. Based on each
customer’s BGP router configuration, you may want to review your BGP
configuration strategy for any routing changes you decide to make. Should
you desire changes to be made, please follow these guidelines: