User`s manual

VDSL2 CO&CPE Modem USER’S MANUAL Ver.A9
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Appendix B: Troubleshooting
1. Symptom: Connected the Co-Modem with CPE-Modem within 300 meters RJ-11 phonecable got only less than 10
Mbit/s.
Cause: Some testing program which is base on TCP/IP protocol such as FTP, Iperf, NetIQ, the bandwidth of testing
outcome will be limited by TCP window size.
Solution: We recommand to test VDSL2 bandwidth best by Smartbit equipment, if you don't have Smartbit, we
recommand test that by IPERF program, and TCP window size must be setted max. 64k, the parameter
as iperf –c co side ip address–I 1 –t 50 –w 65535 for client side.
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