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#### Issues with BT SOGEA-FTTC Service ####
Had my TTB-FTTC 80/20 service change over to BT-SOGEA-FTTC 80/20 and I have noted the following issues:-
Post Upgrade of service:-
1. Service will only SYNC with certain CPE’s – Example Cisco C887 and C927
2. SNR levels are as per the stated rates circa 6.2/6.3 dB for Downstream/Upstream
3. Line KDB indicated High Resistance – Openreach attended FNF – NTE replace with 5c variant
4. Openreach reset the DLM – at time of visit. Openreach also stated that my service was Cooper all the way to the exchange.
5. The equipment that does not achieve SYNC I note while trying to train an “Estimated Loop Length” of 900m is seen.
6. I know my local plant route to serving PCP and that distance is 500m – this was also confirmed by Openreach Engineer who attended site via his line diagnostics.
7. The Exchange that is served from the PCP is 900m from my location. Summary, Property to PCP 500m, PCP to Exchange 400m. Total 900m same indication as the “Estimated Loop Length”
8. Taken equipment to another property served via the same PCP, it is enabled with a TTB-FTTC 40/10 Service – Result all equipment achieves SYNC. Distance noted total 475m, Property to PCP 75m, PCP to Exchange 400m.
9. Had the Profile for the BT SOGEA-FTTC change to 40/10 noted that the SNR level increased to 11.2/6.2 dB Downstream/Upstream – no improvement to achieve SYNC. Profile applied is “Super Stable”.
10. Took equipment to a Property with SKY-FTTC 80/20 and noted that all SYNC and achieve PPP sessions (PPPOE).
Now here is the difference –
11. The “Estimated Loop Length” gave an indication of 338m – the property is served via PCP 4, off the same serving exchange. PCP 4 is 338m away from the Property. Noise Margin (dB): 2.5/6.2 Downstream/Upstream.
The distance to the Exchange is 2.3km – this indicates to me that the modem in the unit has achieved SYNC to the DSLAM in PCP-4 (or adjacent to it). Whereas the connection enabled with the SOGEA service is being served via a DSLAM in the Exchange and not adjacent to PCP-1.
Summary:-
I have ruled out Equipment being the issue – used 2 Vendors Cisco and Digi both with ADSL2+/VDSL2 capable modems.
Cisco – SYNC’s on SOGEA-FTTC, TTB-FTTC and SKY-FTTC
Cisco – “Clear Counters” command result - Drops VDSL Connection if connected to SOGEA-FTTC but remains stable if connected to TTB-FTTC and SKY-FTTC
* Note The same condition is noted on both the C887 and C927 units.
Digi – Cannot achieve SYNC on SOGEA-FTTC, SYNC’s on TTB-FTTC and SKY-FTTC
It would appear that services for SOGEA-FTTC are terminated to a DSLAM that is in the Local Exchange, I make this assumption based on the “Estimated Loop Length” indicated for the SOGEA-FTTC and the TTB-FTTC which are both served by PCP-1.
My understanding for any FTTC based service is that the Digital element should be cross tied to the DSLAM at the PCP for onward delivery to the OLT (Optical Line Terminal) located in the exchange. I am unclear if the Analogue service has been discounted from MDF to PSTN service in the Exchange – however the number previously associated with service is “Not in Service”. So I assume this to be the case.
Cisco Units have the current Firmware – Validated for BT Services
Digi Unit is EOL/EOS – all available firmware’s have been tested.
My next course of Action is to raise a “Special Fault Investigation” with my CP as both Access and Digital services are provided by them.
Any suggestions as to why the above conditions are being noted would be appreciated.
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