the arp aging time of the Cisco 7821 Phone

[gushuhua]

I just encountered a problem that the arp aging time of Cisco 7821 phone. How long is the aging time of this phone type? How to change the aging time of the Phone?
When phone A calls Phone B， Phone A sent the RTP packet of right destination MAC. But the arp cache of the Phone B has not renewed automatically, it sent the RTP packet with the wrong destination mac learned from it's arp cache. The phone A could not receive the RTP packet from phone B and finally it caused the one-way audio issue.

[M02@rt37]

Hello @gushuhua,

do you see with wireshark the fact that phone sent the RTP packet with the wrong destination mac learned from it's arp cache ?

[gushuhua]

I  see it .