[VoiceOps] LNP, tandems, etc.

Wed Aug 29 12:42:27 EDT 2018

It's true that in the metropolitan areas the ILECs will allow you to 
trunk everything to the tandem, but the routing for rural areas is 
handled totally different in some ILEC areas. The old CenturyLink used 
to force carriers in some rural areas to deliver to the end office if 
the office associated with the rate center because it was so far out 
that the office had no local tandem.  Others like the old Qwest 
territories let you route all traffic from the switches that had no 
local tandem over the Access Tandem if you had SPOP (Single Point of 
Presence) language in your agreement. The old BellSouth areas let you 
establish one Multi-tandem supergroup for the entire ILEC area and just 
charged you minutes of use anytime they had to inter-tandem a call.

Every ILEC territory is just a little different, but they all share 
commonalities that they require you to route the LRN NXX to the tandem 
(or EO if there is no local tandem) that it is served by.

Mary Lou Carey

BackUP Telecom Consulting

Office: 615-771-7868 (temporary)

Cell: 615-796-1111

On 2018-08-28 07:25 PM, Erik wrote:
> Most providers simply connect to the tandem at the ILEC. The end
> office transit termination and origination cost is SO LOW that it
> doesn't make since to have a switch or access point at the end office.
> Since most things are ILEC if not all are VOIP everything is coming
> from a centralize switch point. Hopefully all the 1970's billing
> methods will disappear.
> 
> On Tue, Aug 28, 2018 at 1:00 PM, Mike Hammett <voiceops at ics-il.net>
> wrote:
> 
>> Meaning if I thought were true? I had just assumed that Inteliquent
>> did have the connections to every tandem in the LATAs they serve,
>> given that (my thought) that you could only port numbers on the same
>> tandem, so universal coverage would require connections to every
>> tandem. We're actually looking at someone like Inteliquent to expand
>> our footprint.
>> 
>> So I'm supposed to be connected to every tandem in my LATA? In my
>> LATA, there are only two (I believe), but some LATAs (like Chicago)
>> have several. I'm supposed to drag a DS1 (or use Inteliquent, etc.
>> if available) to connect to each one, even if I don't provide
>> service in the rate centers traditionally served by that tandem? It
>> seems like Comcast threw a dart at a dart board in choosing which
>> tandem to connect to vs. going with the one that everyone else in
>> that town uses.
>> 
>> So then I could port a number from any rate center in my LATA (say
>> Savanna) and point it to my LRN, living off of a tandem switch that
>> the Savanna ILEC isn't connected to (from my outside world
>> perspective)? Is there even the LATA constraint? Given the porting
>> limitations I had experienced in the VoIP world, I assumed it was a
>> tandem-by-tandem basis.
>> 
>> So the LERG shows which tandem I need to send traffic to if I want
>> to talk to them, but they could send their outbound calls to a
>> different tandem? My current customer complaint is for calls that
>> we're sending to Comcast, apparently homed off of the other tandem.
>> 
>> If everyone is supposed to be on every tandem, then why can't the
>> tandem I'm on just accept the calls I'm sending to Comcast, since
>> Comcast should be there? Obviously me not being on the other tandem
>> would affect inbound traffic to me.
>> 
>> Is there another service I should be paying Frontier for to get me
>> to the other tandem with some value-add service? I know CenturyLink
>> hops through almost every town going that way (former LightCore and
>> others before route). Frontier or CenturyLink may be able to get me
>> a DS1 to the other tandem if I need that.
>> 
>> I'm aware that I could still be completely missing the mark.
>> 
>> BTW: Thanks for TelcoData. I subscribed a long time ago, but haven't
>> for many ages.
>> 
>> -----
>> Mike Hammett
>> Intelligent Computing Solutions
>> http://www.ics-il.com
>> 
>> Midwest Internet Exchange
>> http://www.midwest-ix.com
>> 
>> -------------------------
>> 
>> FROM: "Paul Timmins" <ptimmins at clearrate.com>
>> TO: "Mike Hammett" <voiceops at ics-il.net>
>> CC: voiceops at voiceops.org
>> SENT: Tuesday, August 28, 2018 5:19:11 PM
>> SUBJECT: Re: [VoiceOps] LNP, tandems, etc.
>> 
>> If that were true, you wouldn't be able to use inteliquent (et al)
>> as your access tandem. Everyone is supposed to be directly or
>> indirectly connected to every tandem in the LATA (which you can't
>> independently verify, as telcodata and the LERG both show
>> terminating tandem information to reach that end office, not what
>> tandems the end office is hooked to to terminate calls.
>> 
>> On Aug 28, 2018 17:47, Mike Hammett <voiceops at ics-il.net> wrote:
>> 
>> I thought you had to be on the same tandem to port a number, but
>> with what our tandem operator (Frontier) is telling me, this isn't
>> the case.
>> 
>> Comcast ported a number from us in town A. The LRN they pointed to
>> is based in town B (per TelcoData). The tandem generally used by
>> carriers in both towns is based in town B. Naturally, we send
>> traffic to that tandem.
>> 
>> The operator of that tandem is telling us that the LRN is actually
>> homed off of a different tandem in our LATA (operated by
>> CenturyLink) in town C. Unfortunately, I can't corroborate this
>> information with TelcoData the only rate center I see off of that
>> tandem in TelcoData is an AT&T town next door.
>> 
>> Where can I read up authoritatively on the porting requirements that
>> would apply to this and related bits of info I should know?
>> 
>> I'm checking on our LERG access as I know that has the authoritative
>> information, but I don't have that access at the moment. Maybe we're
>> not subscribed to it.
>> 
>> Number NPA-NXX in town A:
>> 
> https://www.telcodata.us/search-area-code-exchange-detail?npa=815&exchange=991
>> [1]
>> LRN NPA-NXX in town B:
>> 
> https://www.telcodata.us/search-area-code-exchange-detail?npa=815&exchange=901
>> [2]
>> Tandem in town B:
>> 
> https://www.telcodata.us/search-switches-by-tandem-clli?cllicode=DKLBILXA50T
>> [3]
>> Tandem in town C:
>> 
> https://www.telcodata.us/search-switches-by-tandem-clli?cllicode=DIXNILXA50T
>> [4]
>> 
>> Thanks.
>> 
>> -----
>> Mike Hammett
>> Intelligent Computing Solutions
>> http://www.ics-il.com
>> 
>> Midwest Internet Exchange
>> http://www.midwest-ix.com
>> 
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>> https://puck.nether.net/mailman/listinfo/voiceops [5]
> 
> 
> 
> Links:
> ------
> [1]
> https://www.telcodata.us/search-area-code-exchange-detail?npa=815&exchange=991
> [2]
> https://www.telcodata.us/search-area-code-exchange-detail?npa=815&exchange=901
> [3] 
> https://www.telcodata.us/search-switches-by-tandem-clli?cllicode=DKLBILXA50T
> [4] 
> https://www.telcodata.us/search-switches-by-tandem-clli?cllicode=DIXNILXA50T
> [5] https://puck.nether.net/mailman/listinfo/voiceops
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