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FAX problem with service onramp

I cannot get this fax complete to email,  it cuts himself in half. I recieve this in FXO.The image of fax  I can to see only half other part is cut.Anyone can helpme? Thanks

I have this IOS:

This is my config

fax interface-type fax-mail
mta send server port 25
mta send subject FAX NAE
mta send mail-from hostname
mta send mail-from username $s$
service onramp flash:app_faxmail_onramp.

voice-port 0/1/0

input gain 4
timeouts call-disconnect 1
timeouts wait-release 2
timing hookflash-out 500
connection plar opx 3960
station-id number 5931
caller-id enable

dial-peer voice 13961 pots
service onramp
destination-pattern 5931
incoming called-number .
port 0/1/0
dial-peer voice 13960 mmoip
service fax_on_vfc_onramp_app out-bound
destination-pattern 3960
information-type fax
session target
image encoding MH

Pratik Jhaveri


With the fact that faxes are working to begin with but not completing, it do not think it is a signaling issue.

With T.37 faxes it buffers the fax page information, this then has to be converted to a TIFF video format and then finally converted to a 7 bit MIME mail  atttachment coding. As a result, it uses large amounts of memory. We have found that the gateway routers need large amounts of memory and the IOMEM should be increased to around 10-15% of main system memory.

Said that, it may not definately be the cause of the faxing problems however you can try to increase the IOMEM to a larger amount to see if this does
resolve the issue.

By default the IOMEM is around 12-14 MB. You can add the following command -

memory-size iomem 10

This will boost 10% of your IOMEM. Once done, reload the router and try sending the fax again.

P.S. - Before making the changes, make sure that this router is not heavily utilized from memory perspective.



Hello Pratik , I have the next information attach :

show mem all totals

-show proc mem

sh processes cpu sorted

can you tell me if I Have the neccesary of memory?This for I go to change of parameters that you said.



It seems that the current IOMEM is set to 10%. Go ahead and apply the command "memory-size iomem 15"

Get a scheduled outage window and apply the changes. This will allow you to test faxes and normal calls.




I have seen this issue before. My fix was one of two things.

1. fix slips on the PRI with

network-clock-participate wic 1

network-clock-select 1 T1 0/1/0

2. Check IOS version for the newest version in the series.

rfspirk wrote:

I have seen this issue before. My fix was one of two things.

1. fix slips on the PRI with

network-clock-participate wic 1

network-clock-select 1 T1 0/1/0

This is an FXO, so there is no clocking to be of concern.  Those commands won't work.

Checking memory is a good call as a previous person mentioned.  Check that first.  If the issue persists, note this:

The T37 TIFF writer is fairly sensitive to frame/line issues and has a hard time correcting if an issue in the page data transmission occurs.  You'd need an audio capture of the entire failed fax to identify if this is occurring, though.

We improved sensitivity with 15.1(2)T though, as documented with:


T.37 - minor clock/frame slips may cause truncated pages in tiff image

Hence, it may make sense to run 15.1(2)T1 and observe for behavior.  If you still see issues, you'll need to get an audio recording for a full fax that fails to investigate further, which can pose to be difficult if this is an intermittent issue.

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