Telecom will this week complete trials of R2, an alternative digital telephony protocol which is seen as the answer to a crisis in primary-rate ISDN provision.
An Internet-driven explosion in demand for ISDN resources has taken Telecom--and everybody else--by surprise this year, and prompted the corporation to investigate R2, a loose signalling protocol first formalised by the CCITT standards body in 1984 and sometimes known as “the poor man’s ISDN”.
Telecom spokesman Murray Milner confirms testing is at an advanced stage and had been focused on R2 as a solution for Internet traffic, and more specifically in connecting with the Ascend Max line, a product family of WAN hubs which allow users to aggregate a wide range of digital and analogue applications over a single set of digital access lines.
“We’re looking at R2 as one of a number of options for dealing with the growth in Internet traffic,” says Milner. “That’s something the whole world is looking at. It’s also one of several alternatives for providing an interface to the Ascend boxes.”
The Ascend product seems to be driving almost all Internet-related demand for ISDN. It has become compulsory for most large ISPs because it allows many dial-in lines to be associated with a single number, and also replaces the old, complex systems of terminal servers and modem banks. Xtra, Ihug, Clear, Actrix, Iprolink, GlobeNet and around 20 large corporates are among those using it.
Steve Harrington, managing director of Asnet NZ, which distributes Ascend products, says the ISDN shortage is “a crisis everywhere--the use of primary-rate ISDN has exploded and the uptake of our equipment this year has been in the hundreds. Frankly, no one guessed Telecom would be installing as many as 300 new primary-rates this year.
“What has happened is that our technology relies on the ISDN signalling capabilities for its features--and they’re features that people want. It means no more modems or ISDN TAs and it supports everything, even mobile access via GSM.”
The shortage of ISDN resources seems to be a particular problem at Telecom’s central Auckland Mayoral Drive exchange, where Xtra and Ihug are rumoured to have booked up all new capacity until February.
R2 is far less expensive than ISDN but it lacks some of ISDN’s signalling capabilities, and there are doubts that it is “smart” enough to support the MAX boxes. Telecom’s bench-testing in conjunction with Asnet indicates that it is.
Milner says that a move to R2 will not, however, alleviate a troublesome bug in Telecom’s NEC-designed ISDN switches, which prevents the full use of the Ascend product’s highly useful ability to aggregate hundreds of dial-in lines to a single number.
Industry observers regarded it as significant that Xtra launched its direct-dial service just after NEC delivered a software patch to fix the problem. The patch failed, and Xtra has resorted to providing different access numbers to different groups of customers. Despite this, customers have begun complaining of access difficulties. Milner says there are “various ways of getting around the problem”, but could not indicate when it would finally be fixed.
Adoption of R2 would also allow Telecom to divert Internet applications away from primary-rate ISDN and avoid being caught with its resources down when Clear, Telstra and perhaps others enter the ISDN market in earnest next year.