ASUS AM604g Wireless ADSL 2+ Router and 4-Port Switch Review

The solution from ASUS we are going to talk about today provides Internet access over ADSL network with built-in 4-port Ethernet switch that directly connects up to four PCs without Ethernet switch/hub required, and it will not affect transmission performance. Read more in our review!

by Platon Scheblykin
04/27/2007 | 10:59 AM

In this era of the rapid growth of telecommunications the problem of the last mile is among the most urgent ones. It’s when you have to connect some remote location to the global communication infrastructure. One possible solution is offered by ADSL technology which allows for high-speed data-transfers along telephone networks which are deployed virtually everywhere. In the last few years of its development this technology underwent some changes that had a positive effect on its data-transfer speed as well as connection reliability. ADSL-compatible devices have been evolving, too, from classic Digital Subscriber Line Access Multiplexers (DSLAMs) to IP-based DSLAMs, from simple modems to ADSL routers.


Today, such routers are widely available on the market along with ordinary ADSL modems and differ from common routers in having an ADSL rather than Ethernet interface on their WAN port.

This article is about one such ADSL router, the ASUS AM604g model. It is a SOHO-class device endowed with only basic functionality like routing traffic inside a local network and to the outside world, connecting to client devices via Wi-Fi, accessing the external network via ADSL. This should suffice for a majority of SOHO users, though.

Such devices have long been available from ASUS, and the AM604g has come to replace the AAM6020VI which is out of production now.

Let’s now see what it can do.

Specification and Accessories



Wireless standard

IEEE 802.11b/g

Encoding standard



External dipole antenna

Signal modulation


Operating frequency

2.4 - 2.5 GHz

Nominal data transfer rate

-802.11g: 6, 9, 12, 18, 24, 36, 48, 54Mbps
-802.11b: 1, 2, 5.5, 11Mbps

Transmit power

-802.11g: 14~16dBm (at normal temp. range)
-802.11b: 16~18dBm (at normal temp. range)


-74 ~ -75dBm@54Mbps
-87 ~ -88dBm@11Mbps
-95 ~ -97dBm@1Mbps
(at normal temp. range)

Operating channels

11 for North America, 14 Japan, 13 Europe (ETSI),
3 (non-overlapping)


1 RJ-11 port

ADSL frequency range


Supported types of
ADSL modulation

RADSL (ANSI T1.413 Issue 2)
G.dmt ADSL over POTS (G.992.1 Annex A)
G.dmt ADSL over ISDN (G.992.1 Annex B)
G.lite (G.992.2)
G.hs (G.994.1)
Auto-negotiating rate adaptation
ADSL2 G.dmt.bis (G.992.3)
ADSL2 G.lite.bis (G.992.4)
ADSL2+ (G.992.5)

Supported standard extensions

AnnexA, AnnexM

Possible encapsulation methods

PPPoA, PPPoE, IoA(bridge)

Supported ADSL standards



4 RJ-45 (10/100 BaseT) Fast Ethernet
10/100 Mb/s ports with Auto MID/MIDX

Other interfaces



External 15V power supply


215 x 60 x 42 mm

Additional features


The box contains:

The accessories are quite sufficient for a device of that class. There is nothing missing here.

Exterior and Interior Design

Let us start out with the product exterior. One glance is enough to realize that the AM604g is designed like most other new network devices from ASUS for the SOHO sector. Mac-styled exterior designs are popular these days and ASUS followed the suit creating a hi-tech and discreet case of the AM604g router. The device looks stylish and remarkable. All hints as to what the device can do are hidden inside the white sleek case with a silvery glossy panel that splits the router up horizontally. The case is ventilated passively, as usual, through the vent grids in the top and bottom panels. The router’s top is just a little warm after a few hours of operation, but the bottom is rather hot. It means you should make sure the AM604g is positioned in such a way that there is free circulation of air around it.

There is also another drawback in the router’s exterior design. Instead of putting the wireless interface antenna on the back panel, which is its normal position, they put it on the side panel. This solution is not good due to two reasons.

First, it spoils the one-piece look of the case. The antenna hole is placed right on the glossy band we’ve mentioned above. This leaves a poor impression as if it was not a factory solution, but a whim of a home user who put the antenna connector without thinking about the appearance of the device. We could understand this if there was no space left for one more connector on the front panel or if the antenna connector was attached to the router’s PCB in some specific way, but the connector is actually connected to the PCB with an ordinary flexible cable that could have easily be made longer. And there is enough of room on the back panel for a few more antennas.

Second, the dimensions of the case are larger with the antenna on its side, which may be a problem sometimes.

Otherwise, we’ve got no complaints about the router’s exterior design. The device can be placed horizontally on the desk or hung on the wall using the holes in its bottom.

All of the router’s indicators are located on the front panel while all its connectors are at the back, which is typical of home network devices. The indicators are small icons and dots cut in the opaque layer of the silvery band that goes around the router’s case. Even when not shining, they stand out in contrast on the front panel. It would be even better if the icons were larger, but they are good anyway.

The light from SMD LEDs located on the PCB is routed to the front panel using plastic light pipes that are designed as a one-piece element.

The indicators are bright enough for both light and dark rooms and are visible at any angle of view. The router has a total of 9 indicators (from left to right):

The router’s connectors and controls are all placed on the rear panel. These are (from left to right):

So, we’ve said enough about the router’s appearance. It’s time to take the thing apart. It was not a problem really. We unfastened four screws located under the router’s rubber feet and easily took the two halves of the case apart.

One part comes off from the poles on the other part. It is these poles the screws are actually screwed into.

We can now explore the hardware section of the device.

The router’s components are placed on one PCB, including the wireless communication module. It is wired on the common PCB rather than on a separate one as most other manufacturers do, although there seems to be a seat for a mini-PCI slot on the PCB. The components are all installed neatly and properly. All the capacitors are soldered in – we can’t see empty seats for radio elements here. The PCB is wired well: the components are distributed uniformly, without being too far from each other.

The router’s heart is the BCM6348 chip from Broadcom.

It combines a MIPS processor (with separate data and instruction caches) and an ADSL module. The BCM6348 also offers an AC’97 interface for VoIP equipment, but this interface is not used here. There is an 8-pin connector near the processor:

We are not sure about its purpose because we couldn’t find the pin assignment of the BCM6348, but if the external console is connected via UART, this is perhaps a USB port header.

A single-chip BCM5325 switch, manufactured by Broadcom too, is connected to the processor via a MII interface.

This switch incorporates five Fast Ethernet ports with AutoMDI/MDIX, and the router makes use of four of them.

The router’s memory consists of a 4MB 90ns flash memory chip from Macronix (MX29LV320AT):

...and a 16MB SDRAM chip from ISSI (IS42S32400B-7T, clocked at 143MHz):

The wireless communication module is based on two chips. One is a MAC-level controller from Broadcom’s AirForce One series. It is called BCM4318. The other chip is a 25121 radio module from SiGe.


Firmware and Interface

The previous router from ASUS we tested in our labs had one weakness, rather shabbily made firmware. After we had used the AM604g for some time and read users’ reports at related Web forums, particularly at the ASUS tech support forum, we realized this router had not quite finalized firmware as well. We can’t say it’s totally awful, yet there are some very disappointing things indeed.

The router’s factory firmware has some limitations and defects that can provoke certain problems, sometimes rather serious problems. The four most frequent ones are the following. First, if you enable the logging feature, the router will noticeably slow down after a while or even hang up altogether. Second, there is poor support of multiple PVCs together with traffic forwarding from certain virtual channels to certain router ports. This produced problems when you were trying to use the Internet simultaneously with, say, network TV supplied by your ISP. Third, the router does not support special characters (:, @, etc) in the login field although such characters are employed by some ISPs. And finally, last but not least, you cannot set up the MTU value manually in the router’s settings. Users whose ISPs employ an MTU value other than is set by default in the AM604g suffer from that most. The MTU value can be changed via Telnet, but only until the next router reboot. Some users have also reported a quick weakening of Wi-Fi signal but there have been few such complains and perhaps that was just one defective product batch. Talking about defective batches, an early batch of the router had one hidden error. The physical logical numbers of the LAN ports were confused and, roughly speaking, you had to plug the cable into Port 1 to work with the fourth logical interface.

The latest released firmware solves all the mentioned problems except for the fourth one. It means the AM604g can still work with many ISPs in bridge mode only. The latest firmware version can be downloaded from here: The only confusing thing about this firmware is that it is not listed in download sections of ASUS’ official websites, so its status is not yet quite clear.

Now that it’s all more or less clear about the firmware, it’s time to check out the common method to configure the router, its web interface. It is designed in the AM604g as a web-page with two frames:

The central frame contains settings and messages. The left frame contains a list of pages with settings designed like a directory tree with a max depth of 4 levels. The interface of the pages resembles a settings screen of some Windows program. Seemingly handy, this interface is not exactly user-friendly. The settings are grouped rather illogically and you often have to click on buttons to reach pages that are not shown in the settings tree. In other words, you have to search for the necessary option in several places. We don’t find this web interface convenient in comparison with traditional interfaces that are designed like a typical web-page.

The integrated help system is poor, too. To be more exact, it is missing. The brief remarks at the beginning of each page just can’t be regarded as a normal help system. So, it is even hard to tell at first whether the router’s abundance of setup options is good or bad.

Well, surely it’s good. But a full description of all the settings occupies about 40 pages in the user manual, so we’ll just tell you what settings are stored where. There are about 50 pages in the web interface (not counting hidden pages in), so we’ll just give you a brief description of folders that contain pages with settings and of some particular pages, too. For you to get your bearings, here is the full tree of settings:

Now, let’s see what exactly setup options we have here.

The Device Info folder contains pages that show the current status of the router: general information, a list of established WAN connections, a list of active routes, and lists of clients with an assigned IP address and with an IP address issued by DHCP. Here you can also find the Statistics folder that shows statistical data on LAN, WAN, ATM and ADSL connections.

The Quick Setup page allows you to quickly set the router’s parameters up for WAN, LAN and WLAN.

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On the WAN page of the Advanced Setup folder you can set up parameters of WAN connections. Each setup step is performed on a separate page which is opened as soon as you have completed the previous step.

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The LAN page in the same folder is for setting up LAN connection parameters.

The NAT folder contains parameters of virtual servers, port triggering, and DMZ.

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The IP Filtering settings located in the Firewall folder are necessary to set up IP address-based packet filtering in both directions.

The MAC Filtering page is for setting up filtering rules for MAC-level frames:

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And the Parental Control allows to let outside users in by a schedule:

Routing rules for dynamic and static routes are set up in the Routing folder. The router’s main gateway is specified here, too.

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DNS servers and Dynamic DNS parameters are specified on the pages of the DNS folder.

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The ADSL page is responsible for the supported ADSL modulation types and allows controlling the frequency channels.

On the Port Mapping page you can route multiple WAN connections to the available LAN ports.

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On the IPSec page you can create IPSec tunnels.

On the Quality of Service page the priority of each traffic type is specified for the wired connection.

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In the Certificate folder you can specify your electronic network certificate policy.

The router’s wireless interface settings can be found in the Wireless folder.

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You can specify all the parameters of the wireless module here, from the SSID, number of active channel and encryption to QoS and parameters of the connection channel itself.

On the Diagnostics page you can run a general test of the ADSL connection quality.

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And finally, the Management folder contains all settings pertaining to the router itself.

Here you can make a backup copy of the router’s settings, load a backup copy, set up authorized access to the router, update its firmware, reset it, etc. You can also configure and view the device’s system log here.

That’s all about the router’s settings. As you can see, it has taken long to describe them even very briefly. For the user not to get confused in all this abundance of options, a logical and well-organized interface is needed, but you don’t find one in this router. Hopefully, ASUS will work to improve it. We are now going to test the AM604g in action.


We performed our usual selection of tests: LAN data-transfer rate, WLAN data-transfer rate, ADSL bandwidth, WLAN module coverage. Here is a list of equipment and software we used in our tests:

Here are the results.


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When testing the WLAN connection we enabled WPA-PSK encryption with the TKIP algorithm.


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To test the bandwidth of the router’s ADSL interface we used a DAS-3224 IP DSLAM from D-Link. The appropriate DSLAM’s port was configured for EoA encapsulation, Fast channel type and AnnexM support, which allowed to transfer data with minimum latencies. The EoA encapsulation type corresponds to Bridge connection on the client device (AM604g). We left the physical connection parameters at their factory defaults. The connection quality was high, according to the DSLAM’s internal diagnostics.


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And finally we tested the router’s Wi-Fi interface bandwidth at different distances and with difference obstacles. We measured the signal level in five points:

Point 1: Near the AM604g

Point 2: At a distance of 4 meters without obstacles

Point 3: At a distance of 5 meters + two thin gypsum wallboards

Point 4: At a distance of 6 meters + one brick wall, about 30cm thick

Point 5: At a distance of 17 meters + one thin gypsum wallboard and one 30cm brick wall

So, the router shows good speed in every tested mode. Its ADSL speed might be better, but it is good already anyway. This is a second router from ASUS we’ve tested in our labs that boasts good, even excellent, speed characteristics. The coverage area of the wireless module is impressive, too. The almost straight graph is indicative of a good transmitter. You can’t really be sure about long-distance Wi-Fi connections, but the overall picture is clear.

The AM604g has successfully passed our tests. Its results are good for a mainstream device.


We can’t compare the AM604g ADSL router with the models it has come to replace, so we can’t tell if it is any better than them. But we can say that the new router has its problems. Apart from minor flaws peculiar to this particular model, the main problem is firmware. Considering that it is a second device from ASUS in a row (the WL-500g Premium was the first one) to raise users’ complaints concerning the implementation of this or that function in its firmware, we can see a bad trend here. Coupled with the awkward setup interface, this spoils our overall impression from the AM604g. Hopefully, other network devices from ASUS will have better firmware.

Summing everything up, the AM604g is an exceptional device. It is an average ADSL router that certainly has got a lot of alternatives. The user should decide for himself if this router’s good performance makes up for its potential problems and inconvenient setup interface. The exterior design is a matter of personal taste, too. We wouldn’t recommend this router to people with limited knowledge of network technologies and everything ADSL-related. The abundance of fine-tuning options offered AM604g will be just confusing for them.