Fax never works well over IP but if you have the customer reduce the fax machine's baud rate to 9600 (if capable) it has more consistent results....we always propose our desktop fax solution as a replacement or have them keep it as a POTS line to be shared with alarm/modem/cr card/fax...this also gives them a disaster line in the event of no IP or power, they can plug in any old SLT phone to make an emergency call. Todd Wolf President / COO Office 207.591.6900 Direct: 207.591.6902 Fax: 207.591.6919 twolf at voipnettechnologies.com www.voipnettechnologies.com * * * * * P Save Paper - Do you really need to print this e-mail? Confidentiality Notice: This email message, including any attachments, may contain confidential and privileged information and is for the SOLE use of the intended recipient(s). Any unauthorized review, use, disclosure or distribution of this email and/or its attachments is strictly prohibited. If you are not the intended recipient, please contact the sender by reply email and destroy/delete all copies of the original message. ________________________________ From: voiceops-bounces at voiceops.org [mailto:voiceops-bounces at voiceops.org] On Behalf Of Jeff Anderson Sent: Wednesday, December 15, 2010 5:54 PM To: voiceops at voiceops.org Subject: [VoiceOps] Dynamic T1 Faxing over IP We are experiencing a fair amount of heart burn attempting to support faxing over our Dynamic T1 product. Some customers it works great and others have frequent problems. We currently support dynamic T1's using both Adtran TA900 series and Cisco IAD2400 services routers. The customers fax machines will connect to their PBX that has a PRI to an IAD/TA. We have the IAD/TA configured for SIP signaling to an Acme SBC selecting T.38 as the preferred codec with fallback to g.711 pass-through. We can force a slower speed, disable error correction, disabled VAD but in the end still have very inconsistent results. From a network perspective the QoS is matching and queuing correctly, the circuits are clean and the IP SLA gives us no reason to believe they are having any network drops or jitter. I was wondering if others who have experience with faxing over IP could share what they have learned works best or anything else that may be helpful. Any help is greatly appreciated. Thanks, Jeff