I am relaying a T1 over ethernet, using an Adtran MX408e.
Since it is a TDM interface packets must be received prior to the jitter buffer on the MX408e exhausting. The MX408e only has a max jitter buffer of 100ms. The jitter on my present connection is ~300ms.
Has someone done this with traffic shaping or dummynet? I have been playing with queues to no avail.
It is not VOIP traffic so a short delay will not pose any problems.
I'm not entirely privy to T1 terminology, so I may make some incorrect assumptions.
My question is do you know why the jitter is so incredibly high? T1s are rated for 1-5ms of jitter and Ethernet is typically in the microseconds. You're talking about latencies 100x greater that normal. While the max buffer may be 100ms, you shouldn't be filling a buffer on a synchronous connection.
Are you relaying a T1 over "ethernet" or ethernet then the internet. A good switch should be able to forward frames with latency measured in microseconds, not 300 milliseconds.
The set up looks like this:
+------+ +--------+ |
MOBILE CONNECTION/OPENVPN |
| +-------+ +------+
The T1s are either end are used for relaying telemetry data from two arcane pieces of equipment between power plants a delay of under 2 seconds end to end is acceptable.
The jitter comes when the connection is piped over the mobile connection. Asterisk and FreeSwitch seemed to have some jitter buffering capabilities, but I am not sure how to implement..
The buffer would work like this (assume 1 packet per millisecond):
-Wait and capture 300 packets–->Send 1 packet every millisecond.
I might be confused but wouldn't the 100ms buffer on the mx408e always be the limiting factor in the above scenario?
I think you're going to have a hell of a time trying to get a TDM circuit transported over a 300ms RTT VPN link. No amount of traffic shaping is going to make that any better. SIP trunking would probably be better, but 300ms is a lot for that too.