A strange but works connection using HG259B as a wifi repeater

The connection is a little bit wield. The other router doesn't need any config. 

HG259B is router B

The original router is router A

Router B is from previous internet company. Router A is from the new  internet company. 

The original layout is simple, router A is connected to the fibre box with the WAN port. All other devices can connect to internet through router A's WIFI.

Telephone is connected to router A and working. 

Both routers have 2 telephone ports. But only router A has correct VOIP settings. Router A's company doesn't provide password to login to router A. So there is no way to copy the VOIP settings. 

The problem is that router A's WIFI signal cannot reach as Far as router B. Router B has the same config as router A for internet connection, so use router B for internet connection is OK. but as router B doesn't have VOIP settings,  telephone is not working with router B.

As we cannot enter router A's management portal, we can only do something from router B. The bad news is that Router B doesn't support WDS, so cannot use as a standard WIFI repeater.

The solution I made here is still using router B as a wifi repeater. 

The connection is as such:

Router B's WAN port connects to Fibre box

Router A's WAN port connects to Router B's LAN 1

Router A's LAN 2 connects to Router B's LAN 2

The hardware connection is simple, but wield. As Router A and Router B is already connected using  WAN port and LAN 1, it shouldn't need LAN2 to LAN2 connection. 

The software part is more complex:

1. Router B needs to be config as bridge mode, as below

2. Router B's IP is config to match Router A's domain, in my case, Router A's IP is 192.168.20.1, so I set router B's IP to 192.168.20.254. Also DHCP should be turned off. (So that Router'A DHCP will work).

3. Telephone is still connect to Router A

With this settings, Connect to both Router A's WIFI and Router B's WIFI will work. 

Different from WDS, their WIFI name and password are different. But actually they are the same network. Devices connect to both WIFI and talk to each other.

Questions: If we don't use bridge mode, can we still make it work? I failed once with these settings. But I am not sure If I made some other mistakes. It suppose to work with the following connection:

Router A's WAN port connect to Fibre box

Router B's LAN 1 connect to Router A's LAN 1

Router B change IP to match router A

Router B disable DHCP

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Feng