V.90 Upgrade FAQ

Contents

General issues for x2 and K56flex modems

Should I upgrade to V.90?

Where do I download the V.90 upgrade?

When my ISP upgrades to V.90, will they stop supporting x2/K56flex?

Will upgrading to V.90 make my x2 modem K56flex-compatible or make my K56flex modem x2-compatible?

Are there any V.90 test numbers I can call?

Upgrading K56flex modems to V.90

If I upgrade my K56flex to V.90, will I still be able to connect to K56flex modems at 56K speeds?

How can I tell if the V.90 upgrade installed successfully?

What init strings enable and disable K56flex and/or V.90?

Upgrading x2 modems to V.90

If I upgrade to V.90, will I still be able to connect to x2 modems at 56K speeds?

Why do I get much slower connects after upgrading to V.90?

How can I tell if the V.90 upgrade installed successfully?

What init strings enable and disable x2 and/or V.90?

Can I downgrade a Courier back to x2?

General issues for x2 and K56flex modems

Should I upgrade to V.90?

Until your ISP offers V.90, there's no advantage to having V.90 on your end. If you're currently getting connections faster than 33.6, I'd suggest staying put until your ISP upgrades.

If you have a K56flex modem and a K56flex ISP, you should definitely not upgrade until your ISP upgrades. More info...

The one exception is that 3Com's V.90 upgrades include updated x2 code. If you have an x2 modem and are currently unable to get x2 connections, the upgrade may be worthwhile. The flip side of that coin is that the newer code won't work with ISPs that are using very old x2 code. If that happens, you'll be limited to conventional V.34 speeds (33.6 and slower). More info...

 

Where do I download the V.90 upgrade?

In most cases, you will just need to download a firmware update from the manufacturer. Check the V.90 Upgrade Link Board for links.

The biggest problem for many people will be not knowing who made their modem, or not being able to find the company. It's for reasons like this that I always recommend buying a brand name modem. If you don't know the brand, visit the "Who made my modem" page for help identifying the manufacturer.

 

When my ISP upgrades to V.90, will they stop supporting x2/K56flex?

No. In all of the cases I'm aware of, when the ISP upgrades, they are adding support for V.90. They are not removing support for older protocols (such as K56flex or x2).

 

Will upgrading to V.90 make my x2 modem K56flex-compatible or make my K56flex modem x2-compatible?

No. V.90 is a different protocol.

If you've been waiting for a 56K standard to be compatible with your ISP, hope is near. When you and your ISP upgrade to V.90, you can connect using the V.90 protocol. But, your ISP must upgrade first. Don't jump the gun!

 

Are there any V.90 test numbers I can call?

3Com's test line supports V.90.

 

Upgrading K56flex modems to V.90

If I upgrade my K56flex to V.90, will I still be able to connect to K56flex modems at 56K speeds?

For Lucent-based K56flex modems, yes.

For Rockwell-based K56flex the answer is a definite "no". You'll be limited to a maximum 33.6 connect with the V.90 code loaded, and will have to go back to the K56flex code to get speeds greater than 33.6.

Please note: This does not apply to new modems that support both K56flex and V.90. They have enough memory to support K56flex and V.90 simultaneuously. It only applies to K56flex modems that have been upgraded to V.90 with software, and is caused by limited memory in the modem.

Shane Lord of Sirius Technologies provided this explanation:

Just a bit of info you may or may not know... You mentioned in your news that two other companies have announced that their modems will support V.90 in March, but that they can only use one or the other (V.90 or K56flex).

The reason for this is because the original reference design (and the single chip RCxxx56ACF/xx chipset) supplied by Rockwell to modem manufacturers for K56flex, incorporated 1 meg flash EEPROMs, as the chipset used was limited by the memory it could access.

K56flex, being the highly complex code that it is, takes almost all of the 1 meg flash EEPROM, and therefore there is no further room for extended code expansion (such as V.90 implementation). The need for two firmware revisions loaded at once was not foreseen in the initial implementation of 56k. This is why units based on this design can only have K56flex or V.90 loaded in firmware at any one time, not both.

To support both in firmware, Rockwell have released a new reference design, and a 2 chip solution, that can reference a larger set of memory. All future designed products from the Sirius Technologies group of companies (NetComm/ Banksia/ Simple/ Avtek) will incorporate this.

A Rockwell employee says that Rockwell now has a one chip solution that supports both K56flex and V.90.

 

How can I tell if the V.90 upgrade installed successfully?

Lucent-based modems

Issue an ATI3 in a terminal program, or check the ATI3 response in the Windows 95 Modem control panel.

If the ATI3 response shows firmware version 5 or higher, the modem supports V.90.

Rockwell-based modems

Issue this command in a terminal program: AT+MS=?

A K56flex-only Rockwell-based modem will respond like this:

(0,1,2,3,9,10,11,56,64,69)

A K56flex Rockwell-based modem that has been upgraded to V.90 will respond like this:

(0,1,2,3,9,10,11,12,64,69)

Note that there is now a 12 instead of a 56. The 12 represents support for V.90. The 56 was the K56flex support. These codes are explained on page 43 of Rockwell's AT command reference manuals (Adobe Acrobat required).

 

What init strings enable and disable K56flex and/or V.90?

Most modems should default to using V.90, but you may need to explicitly enable V.90 with some models. It's sometimes useful to be able to disable protocols in order to dial into a particular host.

Which commands you need to use depend on your modem's chipset. Add these commands to the end of your modem init string.

Lucent chipset modems

For Apollo (LT Win Modem) and Mars (LT PCI Win Modem) chipsets:

Enable V.90	-V90=1
Disable V.90	-V90=0
See current -V90 setting with explanation	-V90? in a terminal
Enable K56flex	S38=1
Disable K56flex	S38=0

.

For Venus chipsets (mostly used in external modems):

K56flex only (V.90 disabled)	S109=0
K56flex or V.90*	S109=1
V.90 only (K56Flex disabled)	S109=2

* Which protocol will be used? Assuming that the ISP supports both, it depends on the firmware. Some versions will prefer K56flex, others will prefer V.90.

Rockwell chipset modems

These commands were provided by Jay Price, an application engineer with Computer Peripherals International, and by Rockwell (now Conexant).

For most Rockwell chips except PCI card models:

V.90 preferred (K56flex will still work)*	+MS=12,1
V.90 only, K56flex and V.34 disabled*	+MS=12,1,34667,56000
K56flex preferred (V.90 will still work)*	+MS=56,1
K56flex only, V.90 and V.34 disabled*	+MS=56,1,34000,56000
Disable V.90 and K56flex, use V.34 (28.8/33.6)	+MS=11,1

* Remember that a Rockwell-based K56flex modem upgraded to V.90 no longer supports K56flex. For an explanation, see If I upgrade my K56flex to V.90, will I still be able to connect to K56flex modems at 56K speeds?

For Rockwell HCF chips (used in PCI cards):

V.90 preferred (K56flex will still work)	+MS=V90
K56flex preferred (V.90 will still work)	+MS=K56FLEX
Disable V.90 and K56flex, use V.34 (28.8/33.6)	+MS=V34

 

Upgrading x2 modems to V.90

If I upgrade to V.90, will I still be able to connect to x2 modems at 56K speeds?

In all but one case that I'm aware of, the answer is yes. Upgraded x2 modems will still be able to connect to either x2 or V.90 hosts and achieve faster-than-33.6 speeds. However, see the next question.

The exception is the ActionTec IS560SKV / DT56000 x2 modem. When upgraded to V.90, it loses its x2 code.

 

Why do I get much slower connects to my x2 ISP after upgrading to V.90?

The most likely explanation is that your ISP is using older x2 code. 3Com's V.90 upgrade also includes updated x2 code that has problems when it encounters very old x2 code on the server end. The main symptom is that the modems won't connect at 33.6 or less, but could connect at faster than 33.6 prior to the upgrade.. This was covered in a PC World story by Brian McWilliams.

The solution in some cases is for the ISP to upgrade their x2 code. As a result of these problems, 3Com has changed its policies and will allow ISPs with 3Com/U.S. Robotics equipment to upgrade to newer x2 code at no charge.

According to 3Com, newer versions of the V.90 client code may be less liable to the V.34 fallback problem, so it doesn't hurt to try upgrading your V.90 firmware to the very latest version.

 

How can I tell if the V.90 upgrade installed successfully?

In a terminal program, send the ATI7 command. V.90 should be listed along with the other protocols.

 

What init strings enable and disable x2 and/or V.90?

Most modems should default to using V.90, but you may need to explicitly enable V.90 with some models. Also, it's sometimes useful to be able to disable protocols in order to dial into a particular host. One 56K.COM reader was unable to access his online banking service after upgrading his 3Com Sportster to V.90. Disabling V.90 allowed him to connect to his bank again.

Here are the appropriate commands for controlling the 56K protocol used on 3Com V.90 modems, as provided by John Powell, 3Com Field Engineering Manager. Add these commands to the end of your modem init string.

Note that these are different in some cases from the commands for x2-only modems.

	x2 on, V.90 off	x2 off, V.90 on	Both off	Both on*
Sportster**	S32=66	S32=34	S32=98	S32=2
Courier	S58=32	S58=1	S58=33	S58=0

* Using AT&F1 in the init string automatically enables both protocols.

**Non-U.S. Robotics modems that support x2 generally use the same commands as the Sportster

 

Can I downgrade a Courier back to x2?

Yes. This TotalService page contains an archive of older firmware.