NTL, one of Britain's largest telcos, has proceeded with plans to block all major Internet ports to help prevent worms from spreading across its network.
Last month it blocked port 135. Now it is blocking (inbound only): 137 (UDP), 138 (UDP), 139 (TCP), 445 (UDP & TCP), 593 (TCP), 1433 (TCP), 1434 (UDP) and 27374 (TCP).
"This 'port-blocking' should have little or no effect on your use of the Internet but it will significantly reduce the vulnerability to infection from variants of the Welchia and MSBlast worms," NTL explains in a notice to subscribers.
The Register is carrying this report.