T1 short-haul vs. long-haul

Wed Jul 21 15:04:33 UTC 2004

Robert Boyle wrote:
> At 08:25 AM 7/21/2004, you wrote:
>> o What is "Wet T1 Capable"?  What is it used for and who needs this?
> 
> This is one of the "features" of the new WIC-1DSU-T1-V2. It seems that 
> some DSUs can be powered by the telco remotely. In 15 years of working 
> in communications, I've never seen this, but that doesn't mean it isn't 
> used by some remote telco using old style T1 without HDSL or HDSL2 
> running over the line.
> 
> In almost all cases today, the T1 spam itself will be powered from the 
> CO and the smartjack will convert 2 HDSL pairs or one HDSL2 pair to   a 
> T1 signal with distinct TX/RX pairs.
> 
> Does anyone else have more/better info?

I found something on Cisco's website.  However this seems only to be relevant
for 'long-haul' T1 connection when there is a four-wire going directly to the
central office (and possibly through repeaters).

http://www.cisco.com/en/US/products/hw/modules/ps2641/products_installation_guide_chapter09186a008007cb6d.html

Enabling Wetting Current on the WIC-1DSU-T1-V2 Card

  The WIC-1DSU-T1-V2 card supports wetting current. Wetting current is a small
  amount of electrical current (60 to 140 milliamps) sent from the central office
  to the card to prevent the corrosion of electrical contacts in the card's network
  connection.

  Wetting current may be enabled or disabled by the user. It is controlled by the
  placement of a jumper on connector J2 on the card. Figure5-6 shows the J2 connector
  and the jumper.

  The feature is enabled by connecting pins 1 and 2 of the J2 connector with a jumper.
  It is disabled either by removing the jumper or by connecting pins 2 and 3 of the
  J2 connector.

  The card is shipped with the jumper connecting pins 2 and 3 on the J2 connector,
  which disables the wetting current.

-- 
Andre