While DSL services are more readily available today than they were just 12 to 18 months ago, DSL still isn't widely used to support national or multinational VPN access.There are a couple of reasons for this. If you have a 1,000-site VPN you would likely have to work with three or four service providers to support DSL access to your corporate VPN.Dealing with one provider to manage a VPN is sometimes complicated enough. Throw in three incumbent local exchange carriers and one competitive LEC and you have a logistical headache to deal with. Think about the additional complexities if you add international service providers into the mix.Some carriers are trying to eliminate this headache for users by either using their own local networks or by teaming with LECs and CLECs to offer customers a single point of contact.WorldCom offers its VPN customers DSL access in 55 markets in the U.S., while AT&T says it supports the same feature to customers in 1,300 U.S. cities. Equant is expected to announce this week that it is offering DSL to its IP VPN service customers in seven countries - Australia, Canada, Hong Kong, Italy, Singapore, U.K. and the U.S.It appears that Equant is the only carrier with a formal international DSL-to-IP VPN offering that spans multiple countries.Although Infonet says it will support DSL to its IP VPN wherever symmetrical DSL (SDSL)\u00a0service is available the carrier has not set up deals with specific regional operators. In other words, it sounds like Infonet will work with its customers in areas where SDSL is available to provision the service, but it does not have a formal offering.Both WorldCom and AT&T hinted that international DSL-to-VPN services are on the horizon.Another reason why some users are steering clear of DSL access to their corporate VPN is because performance guarantees aren't up to par. In fact, service-level agreements (SLA) that cover performance guarantees are pretty hard to come by.Equant says that the DSL service providers it is working with are not offering consistent performance guarantees where it can offer users a standard SLA that covers DSL.But if users are paying AT&T, WorldCom or Equant thousands per month to manage your VPN, most are going to want SLAs that cover all aspects of their network.One user says that he would like to move to DSL as an access method to reduce monthly service charges at some sites, but the lack of SLAs are preventing him from doing so. This particular user is sticking with dedicated fractional T-1s. This also means he is likely paying 20% to 30% more per connection by sticking with guaranteed T-1 access where he really only needs DSL.Like this one user, many may rather pay the extra money each month for a stronger SLA than turn to an access service that could go down with no repercussions.