[Asterisk-Users] MTU and Voice Delay (latency??)

Geoff Manning gmanning at zoom.com
Tue Jan 10 15:28:37 MST 2006


Rich Adamson wrote:
> Absolutely not. The MTU is the Maximum Transmission Unit, and sip
> packets are about 214 bytes in size (including all pkt headers). Way
> smaller then the MTU.
> 

If the only thing on my network are these Cisco Phones, would lowering the
MTU encourage more efficient transfer of data as per here:

http://www.voiptroubleshooter.com/problems/mtu.html
http://www.opalsoft.net/qos/VoIP.htm


Here is the breakdown of packets on the port that has the SDSL modem:

SDSL Router
				Amount	% of Whole
64 BytePkts			0		0%
65-127 BytePkts		20257		1%
128-255 BytePkts		3623518	91%
256-511 BytePkts		237087	6%
512-1023 BytePkts		112900	3%
1024-1522 BytePkts	48		0%
Total				3993810	100%

The larger packets I'm sure are the bootloader stuff and config file
downloads, etc.

I do feel like I am reaching for straws here!

Just as an update, the users used to be on two 2mb down/512 up ADSL lines
(PPPoE) (4 users on each) and they never reported a problem. Now that they
are on one SDSL (PPPoA) line (2mb) is when they report the issues.



More information about the asterisk-users mailing list