Our discussion last time of AT&T's move into the local business market with services for very large enterprise sites included a side note that branch-office locations also require back-up alternatives to improve the reliability of their last-mile connections.Branch-office sites face price pressures that often discourage investments in failover links and redundant WAN access CPE - yet users in these locations still require reliable connectivity to corporate resources. A deal recently struck by Covad Communications and New Edge Networks, both business-class broadband service providers, could help.The two companies signed a resale agreement to combine the reach of each company's DSL and T-1 networks. As a result, highly distributed branch-office locations can use a common provider in more places. In many instances, this will likely give smaller sites additional options for diversity between a primary connection and back-up link to protect against last-mile outages. In the case of DSL, these connections are likely to be more affordable - yet with business-class reliability guarantees - than higher-end data services.By virtue of the deal, Covad expands its reach to 600 New Edge Networks central offices in small and midsized cities in eight new states, increasing Covad's footprint to 43 states. Covad says its own network reaches about 45% of U.S. homes and businesses.New Edge Networks - which offers frame relay, ATM, Internet access, virtual private networking, and other services - acknowledged earlier this month that it is actively pursuing acquisitions of broadband carriers.\u00a0 Last year, for example, the company acquired the commercial division of @Home in a bankruptcy auction and hundreds of business data customers from Cable & Wireless.