The magazine of the Melbourne PC User Group
The NetComm V300 VoIP Telephone Adaptor/Router
Nathan and Samuel Pinskier		  
 
The NetComm V300 VoIP telephone adaptor/router is a useful addition to the NetComm VoIP range. The first NetComm SOHO analogue telephone adaptor, the V100 has been available in the marketplace for about a year and promoted by a number of Australian broadband VoIP providers including MyNetFone and more recently Gotalk. The V300 unit reviewed here was provided by NetComm.

V300 Specifications

The V300 has a footprint of 227 mm x 144 mm x 40 mm. Unlike many routers on the market it doesn't have a vertical mounting stand — it sits horizontally — and that can be an issue if space is limited. There is an RJ-11 (phone) port to which you attach your telephone handset, and three Ethernet ports to enable the connection of PCs, switches or other devices on a local network as required.

Connecting to the outside world, one RJ-11 (line) port is for a PSTN phone line and one Ethernet (WAN) port is for the broadband connection.

Key Features Include

  1. PSTN pass-through: This enables all calls, incoming and outgoing, VoIP or PSTN, from the same telephone handset.
  2. A land line lifeline: The ability to access the PSTN in the event that the VoIP service is unavailable
  3. Quality of Service (QoS): A feature designed to protect and maintain voice quality.
  4. Web-based configuration. The unit has a pre configured IP address — you can access it from your browser.
The Package

The V300 comes supplied with a hard copy quick start guide, a CD containing both the quick start guide and a user manual, a telephone cable and an Ethernet cable.

Set Up

The V300 can be connected to your network using a number of configuration options
 
Option 1
The ideal configuration is to connect the V300 directly to your cable or ADSL modem (Figures 1 & 2). In my case this involved connecting the V300 to a Motorola 5100 Surfband cable modem with the Internet provider being Optusnet. The supplied Ethernet cable was connected between the RJ-45 port of the modem and the WAN port of the V300. The router was then connected to an eight port switch (via one of the V300 LAN ports) to enable my PC network to function.

The PSTN land line was then connected to the line port and an analogue handset was connected to the phone port. The V300 is by default configured in WAN DHCP mode so it will automatically obtain a dynamic WAN IP address (which is ideal for cable users). The WAN setup can be changed to either static or PPPoE as required.

As the supplied unit did not have a pre configured VoIP service provider I arranged with MyNetFone to have another prepaid number added to my existing account.

The V300 router features include the standard options such as Network Address Translation (NAT), Port Forwarding, DHCP, DMZ, remote access and basic traffic statistics. There is no configurable firewall facility, no event log or many of the more advanced options available in most SOHO firewall routers these days. Especially concerning is that there is no option to switch off the ping from WAN side.

In manual mode when the VoIP service is unavailable, access to the PSTN land line can be obtained by pressing '##' on the handset. It can also be set to automatic switchover. There is a further option to set the emergency call number access either via your VoIP provider or via land line.

Option 2
In this scenario a more robust firewall/ router can be attached behind the V300 to provide additional security and functionality. I attached my D-Link DI-824 VPN wireless firewall router to one of the V300 LAN ports. The V300 LAN DHCP was enabled and D-Link was automatically assigned a WAN IP address of 192.168.30.2. All PCs on the LAN were connected to the D-Link. The D-Link DI-824 enables users to set up secure IPSec VPN tunnels which in my case are required to provide permanent access to my remote offices. In order for the IPSec tunnels to function in this setup, the VoIP router must support IPSec pass-though.

The NetComm V300 specifications informed of this feature and my tests confirmed this advice. However, it was necessary to enable DMZ on the V300. Note that previously similar tests with the two line Netgear TA612V were unsuccessful.

An alternative there is to use a combination modem firewall router.


Figure 1. Typical Cable Setup
(from the NetComm user guide)
 


Figure 2. Typical ADSL Configuration
(from the Netcomm user guide)

Option 3
The V300 can be connected behind an existing router to operate on the LAN side of your network, after which the browser configuration can be accessed from any PC on the LAN. This is a useful option if you want your existing router to remain the highest in the pecking order. In addition it means that in theory you can easily connect additional ATAs to the LAN. However, you will lose the advantage of the QoS feature but that can be addressed by installing a dedicated QoS VoIP accelerator. I rushed out and purchased a D-Link DI-102 to restore order to my VoIP world.

Comments

The V300 user instructions and configuration utility were fairly easy to traverse and functionality was quickly achieved. It was tested for a period of two weeks and overall, operated well. The V300 browser configuration utility is preferable to the software tool supplied with the V100. The QoS
feature is a significant advancement over the V100 in that it enables the maintenance of higher quality VoIP calls during periods of heavy Internet usage by improving voice clarity and minimising signal break-up. This is of course dependant upon the user having an adequate upload speed. A minimum of 64 kbit/s is commonly specified for VolP to function, however, in reality and as advised by NetComm in its FAQs this can be as high as 106 kbit/s (for DSL) both upstream and downstream traffic.

The PSTN pass-through feature is useful if you wish to avoid the gradual development of telephone handset visual pollution (which admittedly is becoming a real issue in my household). The unit will select VoIP telephony for all outgoing calls (a form of least cost routing) when the broadband connection is available.

When you are using the VoIP service and a PSTN call is received the unit will beep to advise of the incoming call (similar to call waiting). However, you must disconnect from the VoIP call in order to answer the PSTN call. If you are using the PSTN line and an incoming VoIP call arrives you are not notified of the call and the caller receives an engaged signal. This is hardly user friendly. I would suspect that most users would prefer to be advised of all incoming calls and then have the option to place them on hold.

A major disadvantage of the PSTN pass-through feature is that you can access only one line at a time. This would be a disaster in my three teenager household — always on the phone — family. The advantage of VoIP technology is that it offers you easy low cost access to a second outgoing line, so why limit that access?

If you wish to check which line (VoIP or PSTN) is being used for an outgoing call, the only way to determine that is to monitor which line lights up on the V300.

Overall, the V300 is a significant improvement over the V100 in terms of voice clarify and configuration accessibility. However, the PSTN pass-through offers limited benefit as it appears to be essentially a feature designed to circumvent the purchase of an additional handset. The router options of the V300 are fairly rudimentary and the inability to switch off ping from WAN potentially exposes the user to external threats. In short I would not recommend using the V300 as your sole firewall.

Note: At the conclusion of the testing period NetComm released a firmware upgrade which allows additional V300s to be connected behind the one providing the QoS. This feature has not been tested.

About the Authors
Nathan Pinskier is a Melbourne GP with a special interest in IT/IM. He is a member of the Commonwealth Dept of Health & Aging (DOHA) Broadband for Health Working Party and has assisted in the development of security guidelines for General Practice.
Samuel is a year I I student at King David College in Armadale. He has just completed his VCE in Information Processing & Management and hopes to pursue a career in IT/IM.

Reprinted from the December 2005 issue of PC Update, the magazine of Melbourne PC User Group, Australia

[ About Melbourne PC User Group ]