Do Your Database Queries Yourself

CLEC managers discuss avoiding LNP query fees.

[July 20, 2007]

On the ISP-CLEC list in June, SM asked:

Regarding LNP dips I understand the rule is that the N-1 carrier is who should do the LNP query to complete the call. My question is this: Is an access tandem or an intermediate tandem ever considered to be the N-1 carrier?

[FG explained] "...in most cases, the N-1 carrier is the access tandem that the destination switch subtends. It's any switch that has direct trunks to the destination.

If you as a switch owner have direct end office trunks (DEOTs) to any other end office switches, then you need to dip calls that *may* be intended for said switch, so that you know when to use the DEOT. If the LRN is not something you have a DEOT to, then you route the call to the tandem subtended by that LRN's Switch+SHA. That could do its own dip, though your SS7 IAM should pass along the LRN. If you pass it to a tandem undipped, the tandem will dip it.

...The SS7 network is fully interconnected, so you can dip from anybody's STP. The dips are done against the LNP database, which is operated by Neustar. It's possible to complete the entire call without touching the ILEC, if you have other trunks to the destination."

[AB replied] "So ILECs and Verisign aren't the only folks that run STPs? Interesting. I know about NPAC, but I thought the only STPs that had the authority to dip into it properly were the ILEC STPs. What are the rules about setting up an STP that can interface with Neustar directly?"

[FG elaborated] "STPs are, essentially, routers; SS7 is like the Internet, wherein everybody exchanges packets with everybody else. Membership is, of course, rather more exclusive... It's not the STPs that do the dipping, it's the SSPs (switches); they do it via the STPs, the way browsers dip into web servers.

A number of carriers, including CLECs, own their own STPs. If you own an STP you need "B/D" link quads to other STPs. Otherwise your switch uses A-link pairs. Non-ILECs who operate SS7 networks as a major business, competitively, include (besides Verisign) Syniverse and TNSI (Transaction Network Services). The other major competitive player used to be SNET Diversified Services but they're owned by ATT Inc., an ILEC—they're still a big national player though, under the ATT name, and don't act like an ILEC. Also, if you are in more than one ILECs' territory, you can locally connect to either ILEC's STPs under its access tariff. Because of this competition, the FCC removed SS7 from the UNE list in the TRO.

Of course if you're in a remote area, getting to anybody's STPs but your local ILEC's might be rather expensive...."

[CG concluded] "We dip every call before processing where that call suppose to go. It gives me a few advantages.

First, it allows me to setup new porting-in subscribers on my switch in advance before the port happens so when my current subs call those numbers, they route out of the network until the day we port them in.

Second, it gives me good reporting capabilities as where my calls are going (cellular, other clecs, ilec, etc.).

Third, it costs me less then if I would have send it to the tandem as the ILEC charges me for doing dips if I do not, but this is not that important as savings are not that huge.

Finally, it allows me to do more intelligent routing."

— End