DS-30

DS-30 (sometimes DS30) links are used to carry speech and signalling information on DMS, CS1000, Norstar, and BCM products.

Variants

• DS-30
  • Used on DMS family products
• DS-30X
  • Used on Norstar Modular platform to interconnect modules
  • Unknown in what way it's different from other variants
• DS-30Y
  • Used on CS1000E and Meridian 1 platforms
  • Carries same traffic as DS-30X but can be combined in groups of 4 to make DS-30Y superloops
  • Seems to only be used on smaller platforms (non-DMS), possibly predecessor or smaller alternative to DS-512 links?

DS-30X Physical

• Four wires (arrows are controller <-> card)
  • Tx PCM →
  • Rx PCM ←
  • 5.12MHz Clock →
  • 1kHz Frame Sync →

DS-30X Electrical

• Signal levels unknown
• Isolation unknown

DS-30X Logical

• Clocked at 2.56MHz (half the 5.12MHz clock received from the controller)
• Carries 32 channels of PCM voice data
• Each channel consists of a 10-bit word
  • 8 bits of voice data (called a "timeslot")
  • 1 bit of signalling data
  • 1 bit indicating "data valid"
• Signalling data is sent in 24-bit words, one bit at a time in each channel.
  • Sent in both directions, one on Tx PCM and one on Rx PCM