[cisco-voip] ATA 186 functionality across a wireless point to point connection

[Brantley Richbourg]

With a P2P connection I would assume you are dealing with other traffic that is competing for access to this shared medium.  Not to mention interference from others wireless devices.  Even though voice seems "fine" over this connection, fax modems are going to be more sensitive to jitter and latency than the human ear. 

We have ATA 186's connected to fax machines running g711 and they work fine, but they are wired not wireless.  I wouldn't even think of personally trying to support fax over wireless.  Maybe if your fax machines supported t.38 it might work better, but I'm not sure.  

I would verify you have the correct QoS on the access points to make sure there is priority assigned to the RTP traffic and nothing else.  Even with priority queuing, if you have a collistion on thoses access points from the other voice and data traffic, 802.11 will still wait before retransmitting, which will queue up your other voice and data traffic.

If you can you could try another wireless radio medium if you have that available?  We use 802.11A in our office for data, because it less likely other rough Aps will use that wireless spectrum.

My 2 cents.

Brantley
 

-----Original Message-----
From: cisco-voip-bounces at puck.nether.net [mailto:cisco-voip-bounces at puck.nether.net] On Behalf Of Nick Matthews
Sent: Tuesday, March 02, 2010 11:19 AM
To: Go0se
Cc: cisco-voip at puck.nether.net
Subject: Re: [cisco-voip] ATA 186 functionality across a wireless point to point connection

You can try enabling passthrough redundancy on the ATA.

This guide has the steps, and bit 7 should be 1 for "Fax method":

http://www.cisco.com/en/US/products/hw/gatecont/ps514/products_configuration_example09186a00800d698e.shtml#task1

You would want the PSTN gateway to also have modem passthrough with
redundancy enabled.


-nick

On Tue, Mar 2, 2010 at 10:33 AM, Go0se <me at go0se.com> wrote:
> Per the ATA data sheet is says it can "make use of existing Ethernet LANs,
> in addition to broadband pipes such as digital subscriber line (DSL), fixed
> wireless." and it also states that it has a "dynamic jitter buffer".
>
>
>
> However, if you look here:
>
>
>
> http://www.cisco.com.az/en/US/docs/voice_ip_comm/cata/186_188/2_15/english/administration/guide/sip/SIP88APG.html#wp1009476
>
>
>
> it says next to FAX G711 fax pass-through and G711 fax mode that "the
> network must have reasonably low network jitter, network delay, and
> packet-loss rate." In my experience, wireless or not, faxing doesn't handle
> any of the above network issues well at all.
>
>
>
> Thanks,
>
>
>
> Go0se
>
>
>
> My blog:
>
> http://atc.go0se.com
>
>
>
> -------------------------------------
>
> Help Hopegivers International
>
> feed the orphans of India.
>
> http://www.hopegivers.org
>
> -------------------------------------
>
>
>
> From: cisco-voip-bounces at puck.nether.net
> [mailto:cisco-voip-bounces at puck.nether.net] On Behalf Of Leetun, Rob
> Sent: Tuesday, March 02, 2010 8:58 AM
> To: cisco-voip at puck.nether.net
> Subject: [cisco-voip] ATA 186 functionality across a wireless point to point
> connection
>
>
>
> Hi,
>
>
>
> We are trying to make an ATA-186 connected to a fax machine work on a
> wireless point to point connection.  We are using the wireless system called
> Solotec.
>
>
>
> It appears that jitter or latency is an issue, where the fax machine makes
> the connection to the receiving fax machine but drops the connection mid
> stream.  Has anyone had any success with P-2-P wireless faxing with an
> ATA-186?
>
>
>
> Our wireless db is around -30, and voice and data communication is fine.
>
>
>
> Thoughts?
>
>
>
>
>
> Rob
>
>
>
> Robert Leetun
>
> Network Engineer
>
> Boulder County Information Technology
>
> 2025 14th Street
>
> Boulder, CO 80302
>
> 303 441-3866 (W)
>
> 303 441-3983 (F)
>
> rleetun at bouldercounty.org
>
>
>
> _______________________________________________
> cisco-voip mailing list
> cisco-voip at puck.nether.net
> https://puck.nether.net/mailman/listinfo/cisco-voip
>
>

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