7905 working at 10 Mbps half duplex

[ewaizel]

Did any of you have this problem?

These phones are connected to Cisco 3560 sw. After negotiation the switch port ends up using this mode. If I fix the speed and duplex mode in the switch port the 7905 phone does not boot.

Any ideas?

[Brandon Buffin · Accepted solution]

Take a look at the following statement:

"Phones with no PC ports and with 10 Mb switch ports (Cisco 7902, 7905, and 7910 IP Phones) should be allowed to auto-negotiate to 10 Mb, half-duplex.

Because these phones support only 10 Mb Ethernet and their ports cannot be manually configured, the upstream switch port should be set to either AUTO negotiate or 10 Mb, half-duplex. In both cases, these phones will negotiate to 10 Mb, half-duplex."

from this document:

http://www.cisco.com/en/US/products/sw/voicesw/ps556/products_implementation_design_guide_chapter09186a0080447513.html

Hope this helps.

Brandon

[ewaizel]

Good information.

It was a surprise to me to find that half-duplex phones do exist (assuming that a voice conversation is "full-duplex" - I mean, both people talking at the same time.

I assume this is to get a cheaper product.

Thanks again

[yshraybman]

There is absolutely nothing wrong with phone being 10mbps/half-duplex. It is still approximately 100 times more than what's needed for the phone call. Just don't put a hub between switch and a phone(with power cube).