[VoiceOps] More Question about routing

Mary Lou Carey marylou at backuptelecom.com
Wed Sep 9 11:36:44 EDT 2020

True, but you still have to be certified as an IPES (Interconnected VOIP 
provider) to get a STIR/SHAKEN certificate so you have to apply to the 
FCC for that piece.

BackUP Telecom Consulting
Office: 615-791-9969
Cell: 615-796-1111

On 2020-09-09 08:50 AM, Dave Frigen wrote:
> FYI, you do not need your own number pool to apply for STIR/SAHKEN.
> You can use your wholesale provider’s credentials for numbering pool
> requirement. Talk to iconective (PA/Policy Administrator) for details.
> Dave
> From: VoiceOps <voiceops-bounces at voiceops.org> On Behalf Of Zilk,
> David
> Sent: Tuesday, September 8, 2020 4:20 PM
> To: voiceops at voiceops.org
> Subject: [VoiceOps] More Question about routing
> Having come into telephony from the data networking end, rather than
> from a PSTN telephony background, where would one find a good  basic
> to detailed tutorial of how routing of VoIP calls into the PSTN and
> vice versa works?
> I have so far only been involved with routing from our SIP platform to
> and from wholesale service providers, and have not yet had to manage
> our own numbers and peering. With STIR/SHAKEN we may need to get into
> that, and I need to get up to speed.
> Thanks,
> David
> From: VoiceOps [mailto:voiceops-bounces at voiceops.org] On Behalf Of
> Richard Jobson
> Sent: Tuesday, September 8, 2020 12:44 PM
> To: Glen Gerhard <glen at cognexus.net>; voiceops at voiceops.org
> Subject: Re: [VoiceOps] Question about SS7 routing
> Hi Ross
> So in your original email you were wondering about the role of MTP,
> the layer 3 protocol. This keeps tabs on the point codes. If you are
> troubleshooting down to the SS7 messages (MSU’s), SLTM’s &
> SLTA’s tell you what point codes those links are reaching.
> The Global Title Translation uses the SCCP/SS7 protocol when
> connecting to IXC.
> Local Number Portability uses AIN/TCAP to dip the database to
> determine the LRN. But many SS7 operations just troubleshoot this by
> looking at the ISUP protocol where the original calling Party number
> (CGN) appears in the Generic Address Part GAP and the LRN in the
> called party number (CDN) field.
> Cheers
> Richard
> From: VoiceOps <voiceops-bounces at voiceops.org> on behalf of Glen
> Gerhard <glen at cognexus.net>
> Date: Tuesday, September 8, 2020 at 11:47 AM
> To: <voiceops at voiceops.org>
> Subject: Re: [VoiceOps] Question about SS7 routing
> Hi Ross,
> Unless you have an SS7 trunk to an ILEC you don't need to worry much
> about the Point Code. For SIP traffic you just dip the call and route
> on the LRN.
> The Point Code itself is a special format that is assigned to you when
> you set up your SS7 capable switch. Unless you have one of them you
> never need to worry about it.
> ========
> ANSI Point Codes
> ANSI point codes are made up of three groups of digits called the
> network indicator (NI), network cluster (NC), and network cluster
> member (NCM). The values for ANSI point codes depends on the value of
> the pctype parameter of the chg-sid command, either ansi or other. If
> the pctype parameter is set to ansi, the ANSI rules for the ANSI point
> code are used to define the point code. The range of values for an
> ANSI point code with the pctype=ansi parameter are:
> NI – 001-255
> NC – 001-255 (if ni = 001-005) or 000-255, * (if ni = 006-255)
> NCM – 000-255, *
> The pctype=other parameter specifies that the ANSI point codes do not
> meet ANSI standards. The range of values for ANSI point codes with the
> pctype=other parameter are:
> NI – 000-255
> NC – 000-255, *
> NCM – 000-255, *
> The asterisk (*) point code value indicates a single cluster address
> for a cluster point code (for example, 20-2-*) or a network routing
> destination (21-*-*). for more information on cluster point codes, see
> the Cluster Routing and Management Diversity (CRMD) section. For more
> information on network routing point codes, see the Network Routing
> section.
> A double asterisk (**) and triple asterisk (***) can also be used for
> the NC and NCM fields of the ANSI point code, but for only the
> rtrv-dstn, rept-stat-dstn, rtrv-rte, and rept-stat-rte commands.
> A double asterisk in the NCM field of a point code (for example,
> 20-2-**) produces a summary report that shows all point code
> destinations or routes residing in the given cluster (20-2). This does
> not include the cluster point code, if the cluster point code (for
> example, 20-2-*) is provisioned. The following examples (rtrv-dstn and
> rtrv-rte) are reports generated using two asterisks in the NCM field
> of a point code.
> =======
> ~Glen
> On 9/3/2020 10:55 AM, Mary Lou Carey wrote:
>> I'll try to make this as short and sweet as possible even though
>> it's pretty complicated. Point Codes are the 10 digit addresses for
>> a particular switch and LRNs are the 10 digit addresses for a
>> particular connection point that switch is associated with. In the
>> PSTN world, all connections are dedicated and implemented by LATA /
>> Tandem area for Local / IntraLATA traffic. When you get your first
>> NPA-NXX for a LATA / tandem area, you enter it in the LERG (National
>> Routing Database) and populate the tandems (Local, IntraLATA and
>> FGD) that you are connecting to. Then you assign a 10 digit phone
>> number from your NXX block to be your LRN. You add that to both the
>> LERG and NPAC (National Porting Database).
>> Once you've published all your switch information in the LERG and
>> NPAC, then you establish your ISUP trunks with each ILEC you're
>> interconnecting with. You can set up additional trunks with other
>> carriers if you want a cheaper option for routing traffic, but the
>> minimum required is the ILEC. Each carrier's switch will have a
>> distinct point code associated with it so you'll order ISUP trunks
>> to each switch (point code route) you need to be connected to.
>> You'll also associate the distinct LRN for that LATA / carrier
>> tandem area with that trunk group. Usually there's multiple trunk
>> groups per LATA / tandem area so you'll program your routing tables
>> with the NPA-NXXs each trunk group serves. That way when a customer
>> originates a call, your switch can do the LNP dip to find the LRN
>> and send it over the route that the NPA-NXX of the LRN is associated
>> with.  Routing tables can get complicated depending on how many
>> carriers you're connected to. Companies that operate in more than
>> one ILEC area or LATA usually purchase Least Cost Routing software
>> so they can send their originating traffic out over the cheapest
>> route.
>> IXC traffic is routed a little differently because it is routed by
>> CIC (4 digit code that identifies the IXC) rather than by NPA-NXX.
>> They connect to all the ILEC carriers just like the CLECs do, but
>> they populate their routing information in the SMS database instead
>> of the NPAC database. Once the call is dipped, the traffic is
>> delivered in pretty much the same way.....by dedicated trunk group /
>> tandem area.
>> BackUP Telecom Consulting
>> Office: 615-791-9969
>> Cell: 615-796-1111
>> On 2020-09-02 04:46 PM, Ross Tajvar wrote:
>>> Hi all,
>>> I'm trying to understand how routing works in SS7-land. I am
>>> familiar
>>> with portability, and I know (at least in the US) the first step
>>> in
>>> routing a call is doing an LNP dip to get the LRN.
>>> However, it looks like addresses in MTP3 are "point codes" (PCs)
>>> which
>>> are assigned to switches. Calls are set up with ISDN-UP, which is
>>> transported via MTP3. So in order for a call to be set up, the
>>> destination switch's PC must be known. How is the destination PC
>>> determined from the destination LRN?
>>> Thanks,
>>> Ross
>>> _______________________________________________
>>> VoiceOps mailing list
>>> VoiceOps at voiceops.org
>>> https://puck.nether.net/mailman/listinfo/voiceops [1]
>> _______________________________________________
>> VoiceOps mailing list
>> VoiceOps at voiceops.org
>> https://puck.nether.net/mailman/listinfo/voiceops [1]
> --
> Glen Gerhard
> glen at cognexus.net
> 858.324.4536
> Cognexus, LLC
> 7891 Avenida Kirjah
> San Diego, CA 92037
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