vwic-1mft-e1 is a single port e1 WIC. This can be used in a regular hwic slot of a 2800/3800. This card requires that you install PVDM2 chips (DSPs) on the motherboard of the 2800 (if the card is installed on a hwic slot).
With NM-HDV2-2T1/E1, which is a network module has higher density to install up to 4 PVDM2 chips on the network module and has a optional vic slot on the network module. This version of NM-HDV2 also has 2 on board t1/e1 ports. These two onboard ports can be configured as t1 or e1 at the same time. Upto 4 t1/e1 ports may be installed at any time on an NM-HDV2 as long as you populate enough DSPs.
I would recommend you to determine,
a. what type of connection you need to PSTN (t1/e1) ?
b. How many such connections you need ?
If your requirement is < 8, i would recommend not using NM-HDV2 and just use the regular hwic slot on the router, with a vwic-1mft-e1 or similar.
I have a router 1841 and an IP telephony system consist from 30 IP phones, I need an access gateway to call PSTN and PSTN call inside IP phones, I need 2 E1's one primary and a second as backup I have to choose the correct 2 ports-VWIC that should handle these 2E1's, so what should the VWIC be?
1841s are not made for supporting voice cards, just because to packetize voice, you need DSPs. There is no NM slot in a 1800 nor does it have any dsp slots on the motherboard to support voice cards. So its a limitation on the router itself. You need a min of 2800 or better to support voice.
Are you getting this error “Installer User Interface Mode Not Supported. The installer cannot run in this UI mode. To specify the interface mode, use the -i command-line option, followed by the UI mode identifier. The value UI mode identifiers...
The below trick might come handy when you have to add a new node to a cluster but you don't have or is unsure of the security password for the publisher. This procedure has been around for ages.
1) Login into the CLI of the Publisher.