ipDTL takes on broadcast ISDN

ISDN option: ipDTL
ISDN option: ipDTL now supports inbound and outbound ISDN calls

ipDTL, the browser-based application for studio-quality audio links, has been updated to dial and receive calls from ISDN codec units.

ipDTL is an alternative to digital tie lines and IP-based voice codecs for radio. Rather than using dedicated hardware, the tool runs in a browser – specifically Google’s Chrome – on a Mac or PC. This means that almost anyone can potentially contribute to a radio programme or podcast in quality, as long as they have access to a decent soundcard or USB microphone.

However, In:Quality, the company behind ipDTL, has developed a way for studios to use the software to dial out to phone lines. The service, called “Tel”, is subscription based (£10 or $15 a month) and allows unlimited calls to regular landlines, or POTS lines in radio jargon.

The developers have now added support for both outbound (studio originates) and inbound ISDN calls. The Tel service includes ISDN calls at no additional cost, and supports the G722 protocol. This supports audio at up to 64kbit/s and 48KHz, and is widely used by the BBC and other stations.

Although ipDTL added outbound ISDN in October, it has now been updated to support incoming calls too. This should be useful for expert guests or freelance radio contributors who want to receive ISDN calls from studios, as well as for anyone producing voiceovers. The services are currently in beta.

It will also help radio stations who need to take in quality lines from outside broadcast or remote studios, where it makes more sense for the remote end to set up the call.

ipDTL has been tested with Telos Zephyr, Prodys Pronto and Prima codecs and In:Quality has settings for each type of codec box. ipDTL can also connect, using the SIP protocol, to the commonly-used Comrex ACCESS range of IP codec boxes.

A basic ipDTL account costs from £10 a month.