Model -- Dynalink  prestige  660hw-61, model 401315 and mentioned in the pdf manual--Rta 1025w
Problem -- this works with a Linksys 2102 and since instalation, when using the phone, it cuts out for aprox 3seconds about every 60 seconds, noticeable by both parties.
On enquiering with xnet help, the following was their conclusion

From what I can see your ADSL modem is changing the packets coming out
of the 2102 before they get to us. This will cause the issues you are
describing. If you are able see if your router has any kind of ALG
running and if so turn it off for SIP on port 5060.

Have a look at his:
http://www.dynalink.co.nz/cms/uploads/file/Products/Rta1025w/Usermanual.pdf
(Reference to the SIP and ALG are on page 96)

It mentions a SIP ALG which changes the packets. It's under the NAT ALG
Configuration section of the web interface. Find that section and
disable the SIP ALG and you should be sorted

Now, the problem begins   When I enter into the browser -- 192.168.1.1 I get the prestigehw-61 block asking for a password to be entered.   This block for the password already has *** in it. Pressing for this then flashes up aprox **************** and reverts back to the start.   Any other passwords cmd or adm have no effect.
1 The person that set the router up originally is not available
2 I am not very computer literate in these affairs (so please take this into account for any solutions)
Thank you