[c-nsp] Surge protection on leased lines

jp jp at saucer.midcoast.com
Thu Sep 4 12:00:37 EDT 2008


Usually our Telco has gas/carbon arrestors at the NID and they differ 
for pots or T1 as T1 is higher voltage.

Make sure your nid, smartbox, router are all grounded together and to 
the electrical system ground. I suspect they are not if current is 
flowing in and damaging your wic.

I know APC made some ptel series arrestors for T1/ISDN usage for 
protecting the twisted pairs when the rj45/48 interfaces are used. I 
have these and they are good. Too bad you don't have access to that.

On Mon, Aug 25, 2008 at 06:05:07PM +0200, Brian Turnbow wrote:
> Thanks for the response.
> They are external csus but they are "telco property" and they don't want us to touch them.
> We have asked several times that they install  protection coming into the building but no go... 
> They install a remote powered integrated shdsl modem/csu in an all plastic housing and the only place we 
> Have been able to connect a ground is to the v.35 mount on the integrated csu. No help there.
> Lighting strike= burned modem/csu= burned wic
> The v.35 protector would be a try to at least save our wic cards and costs of dispatching a Tech 
> for every passing storm.
>  
> 
> Brian
> 
> -----Original Message-----
> From: cisco-nsp-bounces at puck.nether.net [mailto:cisco-nsp-bounces at puck.nether.net] On Behalf Of Jay Hennigan
> Sent: lunedì 25 agosto 2008 17.34
> To: Cisco Mailing list
> Subject: Re: [c-nsp] Surge protection on leased lines
> 
> Brian Turnbow wrote:
> > Hello,
> >  
> > We have several customers that our having problems every time a storm
> > goes through. 
> > Our national telco company seems to offer no lightning protection on
> > their lines, and every storm causes a line outage and burns up the
> > attached wic.
> > We've made sure the chassis are grounded , but would also like to try
> > and install a surge protection detween the v.35 interface of the telco
> > and our CPEs.
> > I see that Cisco offers a surge protection cable for smart serial
> > interfaces, but not for classic serial interfaces. 
> > I wanted ask what others would recommend / experiences regarding surge
> > protection on leased lines.
> 
> This is an external CSU?
> 
> I think you want it between the telco smartjack and the CSU, not on the 
> v.35.  This should be two pairs of wires.
> 
> First thing to do is ensure that the telco smartjack, the CSU, and the 
> router are solidly connected to a common ground, as this may be the 
> source of the problem if the sneak current is not coming across the 
> leased line.
> 
> There are a number of companies making lightning protectors for twisted 
> pair lines, Reliable Electric and Polyphaser are two.
> 
> But, triple-check the grounding first because if it's common-mode across 
> a ground differential the protectors won't help.
> 
> --
> Jay Hennigan - CCIE #7880 - Network Engineering - jay at impulse.net
> Impulse Internet Service  -  http://www.impulse.net/
> Your local telephone and internet company - 805 884-6323 - WB6RDV
> _______________________________________________
> cisco-nsp mailing list  cisco-nsp at puck.nether.net
> https://puck.nether.net/mailman/listinfo/cisco-nsp
> archive at http://puck.nether.net/pipermail/cisco-nsp/
> _______________________________________________
> cisco-nsp mailing list  cisco-nsp at puck.nether.net
> https://puck.nether.net/mailman/listinfo/cisco-nsp
> archive at http://puck.nether.net/pipermail/cisco-nsp/

-- 
/*
Jason Philbrook   |   Midcoast Internet Solutions - Wireless and DSL
    KB1IOJ        |   Broadband Internet Access, Dialup, and Hosting 
 http://f64.nu/   |   for Midcoast Maine    http://www.midcoast.com/
*/


More information about the cisco-nsp mailing list