Ok,
hciconfig - of my client is:

hci0:   Type: USB
        BD Address: 00:10:60:A5:81:68 ACL MTU: 192:8 SCO MTU: 64:8
        UP RUNNING PSCAN ISCAN
        RX bytes:254 acl:0 sco:0 events:28 errors:0
        TX bytes:379 acl:0 sco:0 commands:20 errors:0
        Features: 0xff 0xff 0x0f 0x00 0x00 0x00 0x00 0x00
        Packet type: DM1 DM3 DM5 DH1 DH3 DH5 HV1 HV2 HV3
        Link policy: RSWITCH HOLD SNIFF PARK
        Link mode: ACCEPT MASTER
        Name: 'EnviCartello'
        Class: 0x820100
        Service Classes: Networking
        Device Class: Computer, Uncategorized
        HCI Ver: 1.1 (0x1) HCI Rev: 0x20d LMP Ver: 1.1 (0x1) LMP Subver: 0x20d
        Manufacturer: Cambridge Silicon Radio (10)

And the hciconfig of my server is :

hci0:   Type: USB
        BD Address: 00:10:60:29:3B:9A ACL MTU: 192:8 SCO MTU: 64:8
        UP RUNNING PSCAN ISCAN
        RX bytes:241 acl:0 sco:0 events:28 errors:0
        TX bytes:373 acl:0 sco:0 commands:20 errors:0
        Features: 0xff 0xff 0x0f 0x00 0x00 0x00 0x00 0x00
        Packet type: DM1 DM3 DM5 DH1 DH3 DH5 HV1 HV2 HV3
        Link policy: RSWITCH HOLD SNIFF PARK
        Link mode: ACCEPT MASTER
        Name: 'PROMOPC'
        Class: 0x820100
        Service Classes: Networking
        Device Class: Computer, Uncategorized
        HCI Ver: 1.1 (0x1) HCI Rev: 0x175 LMP Ver: 1.1 (0x1) LMP Subver: 0x175
        Manufacturer: Cambridge Silicon Radio (10)