Moving fibre trunks: interruptions?

Alain Hebert ahebert at
Fri Sep 1 20:12:47 UTC 2017


     Being somehow familiar with how things operate when it involve 
Quebec Govt and the Fed Govt...  Expect hell.  Pray for purgatory.  
Rejoice if it takes less than 3 months.

     PS: At least we have very good, and dedicated, cabling crews.


     But yeah, there is work being done to reduce the downtime to a 
manageable timeframe.  If not simply redundancy being added to allow for 
the time to splice that bad boy.

Alain Hebert                                ahebert at
PubNIX Inc.
50 boul. St-Charles
P.O. Box 26770     Beaconsfield, Quebec     H9W 6G7
Tel: 514-990-5911    Fax: 514-990-9443

On 09/01/17 14:44, Jay Hanke wrote:
> I'd expect at least a couple of hours of outage while the cable is reconnected.
> When doing the move on the live cable (assuming 1 cable). There will
> be a splicing crew at each end of the move. They will then break a
> tube or ribbon at a time and splice into the new cable.
> Splicing unused portions of the cable and then moving patches is also
> done. In my experience, it's much more common to resplice on the
> existing strands.
> A large cable will take quite a while to resplice, likely more than
> just overnight depending on the size of the cable.
> Jay
> On Fri, Sep 1, 2017 at 1:32 PM, Jean-Francois Mezei
> <jfmezei_nanog at> wrote:
>> A large highway interchange is being rebuilt in Montréal (Turcot) and
>> this requires that the CN mainline tracks out of downtown be moved a few
>> hundred metres to the north for a couple of kilometres until it rejoins
>> the existing alignment.
>> Part of the contract involves the cost of moving the fibre trunks along
>> with the tracks. (old alignment will become commercial properties).
>> So they have new cable that goes through the new alignment and joins the
>> old one at both ends.  So they'll have hundreds of strands to splice.
>> When doing that type of work, how much downtime can be expected for each
>> strand?
>> Would they typically use patch panels in central offices to move a
>> customer to a spare strand while they splice their assigned strand to
>> use the new cable segment (and then move traffic back to that assigned
>> strand?). Or would they switch customers around to new strands and
>> update their documentation on which customer is on which strand?
>> Or do they do nothing at patch panels in COs and just take whatever time
>> it is needed to have crews at both ends of the work site splice each
>> strand at same time (I assume about 5 minutes outage for each strand?)
>> Would they normally involve the customer advising them of upcoming
>> outage? Would the folks working trackside be limited to overnight hours
>> to make outages less significant, or do they work around the clock ?

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