Understanding and diagnosing DDI dialling restrictions 2

[MikeyTen4]

Hi everyone, happy new year

Someone in my organisation has discovered that numbers beginning 0808 can't be dialled. I'm in the UK, this is a Freephone number and shouldn't be blocked. Number restrictions aren't something I'm very familiar with, having touched upon it in the past but not for a long time, so I'd appreciate a bit of help unravelling why this number can't be reached and how to overcome that.

So far I've had a dig around online and it's led me to do the following. There's every chance that I'm misunderstanding something here, or that there may be other things to look at which I'm missing.

First of all, some info to begin with. We use NCOS tables for common call restrictions or allowances - e.g. commonly phones use NCOS 5 to reach standard outside lines in the UK, while we provide NCOS 6 to phones which need to make international calls. We use '9' as the access code for outbound dialing, which is confirmed as relating to AC1 via a LD 86 ESN print out.

With this info I went into LD 90 and printed out the SPNs under AC1 starting "08".

REQ  prt
CUST 0
FEAT net
TRAN ac1
TYPE spn
SPN  08

SPN  080
FLEN 11
ITOH NO
CLTP NONE
RLI  9
SDRR NONE
ITEI NONE

From here I went to LD 86 and printed RLI 9...

REQ  prt
CUST 0
FEAT rlb
RLI  9


RLI  9
ELC  NO
ENTR 0
LTER NO
ROUT 100
TOD  0 ON  1 ON  2 ON  3 ON
     4 ON  5 ON  6 ON  7 ON
VNS  NO
CNV  NO
EXP  NO
FRL  0
DMI  0
CTBL 0
FCI  0
FSNI 0
BNE  NO
SBOC RRA
COPT 1
IDBB DBD
IOHQ NO
OHQ  NO
CBQ  NO

ENTR 1
LTER NO
ROUT 102
TOD  0 ON  1 ON  2 ON  3 ON
     4 ON  5 ON  6 ON  7 ON
VNS  NO
CNV  NO
EXP  NO
FRL  0
DMI  0
CTBL 0
FCI  0
FSNI 0
BNE  NO
SBOC RRA
COPT 1
IDBB DBD
IOHQ NO
OHQ  NO
CBQ  NO

ISET 0
NALT 5
MFRL 0
OVLL 0

Based on my reading, I'm under the impression that the value listed next to FRL is what I should be interested in. I gather that this value (0 in the case of the above) relates to the CRNO number as listed via a LD 49 FCR print...

REQ  prt
TYPE fcr
CUST 0
CRNO


CRNO   0
INIT DENY
ALOW 111
     112
     101
     911
     999
     **

CRNO   1
INIT DENY
ALOW 111
     112
     101
     911
     999
     01604236452
     08456404040
     08001111
     08000560566

CRNO   2
INIT DENY
ALOW 111
     112
     101
     911
     999
BYPS **

CRNO   3
INIT ALOW
DENY 1
ALOW 111
     112
     1410500
     1410845
     1410808
     1410800
     101
DENY 0
ALOW 0500
     0845
     0808
     0800
DENY **

CRNO   4
INIT ALOW
DENY 123
     141123
     141155
     14103
     14104
     14105
ALOW 1410500
DENY 14106
     14107
     14108
ALOW 1410845
     1410870
     1410808
     1410800
DENY 14109
     14100
     155
     04
     05
ALOW 0500
DENY 06
     07
     08
ALOW 0845
     0870
     0808
     0800
DENY 09
     00

CRNO   5
INIT ALOW
DENY 118
     123
     141123
     141155
     141091
     141090
     14100
     155
     07021888000
     091
     090
     00

CRNO   6
INIT ALOW
DENY 123
     141123
     141091
     141090
     14100
     07021888000
     091
     090

CRNO   7
INIT ALOW
DENY 141155
     141091
     141090
     155
     07021888000
     091

CRNO   8
CRNO   9
CRNO  10
CRNO  11
CRNO  12
CRNO  13
CRNO  14
CRNO  15
CRNO  16
CRNO  17
CRNO  18
CRNO  19

Now, this is where I get totally confused and question my understanding of any of the above. Firstly, I seem to remember from past experience that CRNO relates to NCOS - correct or not? If so, then the phones which cannot dial 0808 numbers are using NCOS (CRNO) 5, which as you can see above denies access to a particular set of numbers, but none starting "08". Come to think of it, I can't immediately see how CRNO 5 would prevent dialling of international phone numbers either (which NCOS 5 does), so maybe CRNO and NCOS aren't the match I think? Past that point, CRNO 0 is tightly locked down, allowing only calls to emergency services. So I suspect this isn't what I should be looking at either.

This side of things is all pretty alien to me, but I do my best to understand. If someone can attempt to guide and educate me on the matter then that would be great.

Cheers
Mike

** EDIT **
A little more reading (this actually) has cleared up that FRL equates to NCOS in my organisation (confirmed via a LD 87 NCTL print). So I'm pretty sure I've gone wrong somewhere above, since the phones which can't dial 0808 numbers certainly don't have NCOS 0 applied to them. A phone which a colleague used to test dialling an 0808 number from has NCOS 5 applied to it, as do practically all of our phones, as mentioned.

 

[Firebird Scrambler]

I have looked at your query and so far, everything you have checked is what I would have done and it all looks to be fine. My question is what type of outgoing trunks are you using?. Go into LD 21 and do

"LTM". My guess is that they are either DASS or ISDN30e digital trunks. Then print out the channel TN's against each route in LD 20. Also, check what number of digits are being dialled for the 0808 numbers as sometimes the "FLEN" needs to be reduced to "10" or even "0". 11 should normally be fine.

Finally set up a trace in LD 80 to see what digits are dialled out to line and also see if it fails at a particular digit length.

Firebird Scrambler

Nortel & Avaya Meridian 1 / Succession & BCM / Norstar Programmer

Website =

http://somertel.myfreesites.net

linkedin

 

[bignose21]

so normally it all maps through but the NCOS is related to an FRL in NCTL in LD 87 (Take prompts out of the below just left in the NCOS-FRL mapping)

REQ prt
CUST 0
FEAT nctl
NRNG 5

NCOS 5
FRL 5

Then in your RDB you can see what FRL to FCR so often 1-1, 2-2,...7-7 for PSTN trunks, default is all mapped to 0 but in your config that would bar everything so in the RDB you would see say:

FRL 0 0
FRL 1 1
FRL 2 2
FRL 3 3
FRL 4 4
FRL 5 5
FRL 6 6
FRL 7 7

So I yours looks like that then NCOS 5 would use FCR 5 and as you say 080 would be allowed

CRNO 5
INIT ALOW
DENY 118
123
141123
141155
141091
141090
14100
155
07021888000
091
090
00
Because the default(INIT) is allow and 080 is not in the Deny list, hope that helps with understanding how it works. As barring looks good I would normally start with the DCH MON on and take a look at the messaging, make sure number is going out with correct digits and Type. If you see a setup message going out that would take barring off the table straight away, and on the messaging see why it fails I guess. You can always post messaging back here if you need help.

 

[MikeyTen4]

Hi both. Thanks very much, this is great. Good to know I'm on the right path, but obviously there's something more going on here.

Firebird Scrambler - We're using ISDN30 trunks, all "EURO" rather than DASS. We've got 5 of these, all configured under a single route (100). Printing LTM does list the trunk member TNs, all 150 of them, but I'm not sure what you're suggesting I could do with these in relation to the issue. Is there something else I could look at using these which might be effecting the ability to dial 0808 numbers? The FLEN part, I wondered about this actually... the 0808 number in question is 11 digits, so I expected that to be fine. I guess I could change it as you've suggested and test the result - there shouldn't be any effect on dialling anything other than numbers starting 080 anyway (correct?).

Bignose21 - Our NCOS / FRL mapping looks just like your example, as does our FRL / FCR mapping too. 1-1, 2-2, 3-3, etc. It's good to know I'm on the right track at least - that NCOS 5 should allow dialling to 0808 numbers. So, there's something else preventing it. This is based on the fact that I said myself that our phones have NCOS 5 applied of course though - did I go wrong with my initial investigation steps, where I looked at the SPN, then the RLI from there (9), which listed FRL 0. Though I didn't fully understand, I took that as an indication that calls to 080 numbers were somehow being pushed through NCOS 0, even though the phone used to dial the 0808 number has NCOS 5 applied. This was the part I ended my original post with, where I said I was confused. Basically I guess I'm not sure what pritng out the SPN and the RLI have actually provided me with if not what I thought.

Anyway this is all great stuff, thanks very much for your help so far. I'll go through the process and tracing things as both of you have suggested. I'll bear in mind what you've said I should look out for. I'll certainly be back with the results if I need more help.

Thanks very much guys.

 

[bignose21]

So is phones CLS TLD? is TGAR/TARG barring enabled (Print the ESN in LD 86 YES/NO at bottom against TGAR) if it is on YES then make sure that the TGAR on the phone is not the same as TARG on the RDB. Also enable the DCH Messaging and make a call see if it is refused by carrier for example