A couple of weeks back I wrote a short “blog” about the end of life for Alcatel 2801 DTU and a migration path for this type of deployment.
This new migration path comes with a replacement card for the 28LC card; the new Alcatel GSLC line card. In summary this card works in two modes.
1. Again with a proprietary NTU ( Symmetricom Go-Wide2.3). This unfortunately is no longer in production and hard to source.
2. A 3rd party G.991.2 compliant NTU.
The second part is where the problem lies as many so-called compliant units wouldn’t work with the Alcatel GSLC card.
We at Xbridge have tested a few G.991.2 SHDSL modems, and so far only one modem has successfully passed all lab tests. This is the
Digitel 2/4W G.SHDSL.bis Access CPE.
The Digitel Modem comes in 2 flavors, 2 and 4 wire mode of operation and they can both work in stand alone mode (master-slave).
The choice of modem is the 2 wire since the GSLC line card only works in a 2-wire mode. One may deploy the 4-wire NTU, but would have to be configured to 2-wire operation.
This new migration path comes with a replacement card for the 28LC card; the new Alcatel GSLC line card. In summary this card works in two modes.
1. Again with a proprietary NTU ( Symmetricom Go-Wide2.3). This unfortunately is no longer in production and hard to source.
2. A 3rd party G.991.2 compliant NTU.
The second part is where the problem lies as many so-called compliant units wouldn’t work with the Alcatel GSLC card.
We at Xbridge have tested a few G.991.2 SHDSL modems, and so far only one modem has successfully passed all lab tests. This is the
Digitel 2/4W G.SHDSL.bis Access CPE.
The Digitel Modem comes in 2 flavors, 2 and 4 wire mode of operation and they can both work in stand alone mode (master-slave).
The choice of modem is the 2 wire since the GSLC line card only works in a 2-wire mode. One may deploy the 4-wire NTU, but would have to be configured to 2-wire operation.
From our initial set-up tests we found that unless the correct S/W code is preloaded on the Newbridge GSLC card as well as the modem’s firmware being of the correct release then the unit would not synchronize with the GSLC line card.
The Digitel modem has 2 data ports; V.35 and an E1 G.703. If the mode
m was used back to back i.e. one as a Master and one as a Slave then both ports could be used simultaneously, however when connecting just one modem directly to the Newbridge GSLC card then only one port could be used at any one time. The V.35 is more of interest because that compares to the data port of the 2801 DTU.
Whilst the E1 port could be used to replace the HDSL Lim (90-2380-01) when connecting Newbridge 2902 Mux (90-2904-01) via copper back to the central site, or for simply offering Full or fractional E1 services to the client.
The Digitel modem has 2 data ports; V.35 and an E1 G.703. If the mode
m was used back to back i.e. one as a Master and one as a Slave then both ports could be used simultaneously, however when connecting just one modem directly to the Newbridge GSLC card then only one port could be used at any one time. The V.35 is more of interest because that compares to the data port of the 2801 DTU.Whilst the E1 port could be used to replace the HDSL Lim (90-2380-01) when connecting Newbridge 2902 Mux (90-2904-01) via copper back to the central site, or for simply offering Full or fractional E1 services to the client.
"It is worth noting that this modem is backward compatible with the
older Newbridge DTUs namely the 2752s, 2753s etc, offering further flexibility "
Here are the test scenarios;
1. A TTC Bert Tester connected to the Digitel Modem and a loopback set within the Newbridge.
2. A TTC Bert Tester connected to an E1 card in the Newbridge and a loopback (both soft and hard) set on the G.SHDSL Modem.
3. A TTC Bert Tester connected to one Digitel Modem and a loopback set on another Digitel Modem/Newbridge 270x/ Newbridge 275x connected to the same line card. (normal deployment)
4. A TTC Bert Tester connected to one Digitel Modem and a loopback set on another Digitel Modem/ Newbridge 270x/ Newbridge 275x connected to a different line card in another Newbridge Mux.(normal deployment)
In summary here are the Pro & Cons of using this CPE.
Pro’s
Flexibility of using either V.35 or E1 Ports (75 Ohm / 120Ohm)
Front Panel buttons for providing local loop’s & remote loops for diagnostics
Far superior line/distance performances in comparison to the Newbridge HDSL line coding.
Pro’s
Flexibility of using either V.35 or E1 Ports (75 Ohm / 120Ohm)
Front Panel buttons for providing local loop’s & remote loops for diagnostics
Far superior line/distance performances in comparison to the Newbridge HDSL line coding.
Con’s
No remote management of the modem as Newbridge uses propriety CPSS management protocol.
Unable to change signaling control leads and parameters remotely from the Newbridge 56020 network management platform. Unable to remotely downgrade or upgrade the circuit speed. This task would have the be done locally on the modem via the VT100 terminal interface.
Conclusion
The two main advantages are lower NTU cost and availability, whilst offering a migration path for customers struggling to source 2801 modems. The Digitel CPE is a carrier class modem and has a wide installed base amongst many PTT’s and carriers.
The main and only disadvantage is remote management. Since it’s not proprietary and doesn’t use CPSS (Alcatel Management Protocol), one has to locally configure the Modem (usually the data interface speed via the serial port before deployment).
Since this report we have now conducted trials in West Africa with a major PTT and have successfully demonstrated this modem in the field.
Xbridge Services will now seek distributorship from Digitel for further supply of this modem.
The datasheet for this modem can be found at
http://www.xbridgeservices.com/department/download_centre/
For pricing please contact us
http://www.xbridgeservices.com/action/contactus/
No remote management of the modem as Newbridge uses propriety CPSS management protocol.
Unable to change signaling control leads and parameters remotely from the Newbridge 56020 network management platform. Unable to remotely downgrade or upgrade the circuit speed. This task would have the be done locally on the modem via the VT100 terminal interface.
Conclusion
The two main advantages are lower NTU cost and availability, whilst offering a migration path for customers struggling to source 2801 modems. The Digitel CPE is a carrier class modem and has a wide installed base amongst many PTT’s and carriers.
The main and only disadvantage is remote management. Since it’s not proprietary and doesn’t use CPSS (Alcatel Management Protocol), one has to locally configure the Modem (usually the data interface speed via the serial port before deployment).
Since this report we have now conducted trials in West Africa with a major PTT and have successfully demonstrated this modem in the field.
Xbridge Services will now seek distributorship from Digitel for further supply of this modem.
The datasheet for this modem can be found at
http://www.xbridgeservices.com/department/download_centre/
For pricing please contact us
http://www.xbridgeservices.com/action/contactus/
2 comments:
I have tested this GSLC Card with RAD ASMI-52 and it works just as the Digitel/4W G.HDSL
Many thanks for the comment,
I will procure one of these for our own in house tests. Are you able to remotely manage the RAD modem and change the interface speeds or does it have to be done locally?
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