This is a read-write setting specifying the default fax transmit rate for calls on this VoIP peer, where a value of none disables the fax relay feature entirely and any other value enables it at that rate. An admin uses this the same way as the ATM peer's equivalent object, to control both whether fax relay is active and at what speed faxes are handled over the IP network. For example, disabling fax relay by setting this to none on a peer that never carries fax traffic avoids unnecessary fax-detection overhead on that peer.