NFAS with D-Channel Backup

To configure NFAS on PRI groups, perform the following steps.

Note

When a backup NFAS D channel is configured and the primary NFAS D channel fails, rollover to the backup D channel is automatic and all connected calls stay connected. If the primary NFAS D channel recovers, the backup NFAS D channel remains active and does not switch over again unless the backup NFAS D channel fails.

1.    enable

2.    configure terminal

3.    controller {t1 | e1} controller-number

4.    pri-group timeslots range nfas_d primary nfas_interface number nfas_group number

5.    pri-group timeslots range nfas_d backup nfas_interface number nfas_group number

6.    pri-group timeslots range nfas_d none nfas_int number nfas_group number

7.    exit

To configure a VoIP dial peer for NFAS voice, perform the following steps.

Note	Dial peers are used by the Cisco IOS voice stack for handling calls going from the PSTN to the VoIP side or vice versa. The dial-peer configuration for each NFAS controller should contain the primary of the NFAS group.

1.    enable

2.    configure terminal

3.    dial-peer voice tag voip

4.    port controller :D

5.    exit

To disable a channel or interface, perform the following steps.

Note	You can disable a specified channel or an entire PRI, thus taking it out of service or put it into one of the other states that is passed in to the switch.

1.    enable

2.    configure terminal

3.    interface serial controller-number : timeslot

4.    isdn service [dsl number | nfas_int number] b_channel number state{0 | 1 | 2}

5.    isdn service [dsl number | nfas_int number] b_channel number state {0 | 1 | 2}

6.    exit

1.    show dial-peer voice

2.    show isdn nfas group

3.    show isdn service

4.    show isdn status

5.    show running-config

Router# show dial-peer voice
VoiceOverIpPeer1
        information type = voice,
        tag = 1, destination-pattern = `',
        answer-address = `', preference=0,
        numbering Type = `unknown'
        group = 1, Admin state is up, Operation state is down,
        incoming called-number = `', connections/maximum = 0/unlimited,
        DTMF Relay = disabled,
        modem passthrough = system,
        huntstop = disabled,
        in bound application associated: DEFAULT
        out bound application associated:
        permission :both
        incoming COR list:maximum capability
        outgoing COR list:minimum requirement
        type = voip, session-target = `',
        technology prefix:
        settle-call = disabled
        ip precedence = 0, UDP checksum = disabled,
        session-protocol = cisco, session-transport = udp, req-qos = best-effor
        acc-qos = best-effort,
        fax rate = voice,   payload size =  20 bytes
        fax protocol = system
        fax NSF = 0xAD0051 (default)
        codec = g729r8,   payload size =  20 bytes,
        Expect factor = 0, Icpif = 20,
        Playout: Mode adaptive,
        Expect factor = 0,
        Max Redirects = 1, Icpif = 20,signaling-type = cas,
        CLID Restrict = disabled
        VAD = enabled, Poor QOV Trap = disabled,
        voice class perm tag = `'
        Connect Time = 0, Charged Units = 0,
        Successful Calls = 0, Failed Calls = 0,
        Accepted Calls = 0, Refused Calls = 0,
        Last Disconnect Cause is "",
        Last Disconnect Text is "",
        Last Setup Time = 0.

Router# show isdn nfas group 1
ISDN NFAS GROUP 1 ENTRIES:
The primary D is Serial1/0:23.
The backup D is Serial1/1:23.
The NFAS member is Serial2/0:23.
There are 3 total nfas members.
There are 93 total available B channels.
The primary D-channel is DSL 0 in state INITIALIZED.
The backup D-channel is DSL 1 in state INITIALIZED.
The current active layer 2 DSL is 1.

• Examples
  

The following example configures ISDN PRI and NFAS on multiple T1 controllers of a Cisco 7500 series router. The D-channel of T1 1/0/0 is configured as primary D-channel and T1 1/0/1 is configured as backup D-channel. Once you configure the NFAS primary D channel, that channel is the only interface you see and have to configure.

version 12.x
service timestamps debug datetime msec localtime show-timezone
service timestamps log datetime msec localtime show-timezone
service password-encryption
!
hostname travis-nas-01
!
aaa new-model
aaa authentication login default local
aaa authentication login NO_AUTHENT none
aaa authorization exec default local if-authenticated
aaa authorization exec NO_AUTHOR none
aaa authorization commands 15 default local if-authenticated
aaa authorization commands 15 NO_AUTHOR none
aaa accounting exec default start-stop group tacacs+
aaa accounting exec NO_ACCOUNT none
aaa accounting commands 15 default stop-only group tacacs+
aaa accounting commands 15 NO_ACCOUNT none
enable secret 5 $1$LsoW$K/qBH9Ih2WstUxvazDgmY/
!
username admin privilege 15 password 7 06455E365E471D1C17
username gmcmilla password 7 071824404D06140044
username krist privilege 15 password 7 0832454D01181118
!
call rsvp-sync
shelf-id 0 router-shelf
shelf-id 1 dial-shelf
!
resource-pool disable
!
modem-pool Default
 pool-range 1/2/0-1/2/143,1/3/0-1/3/143
!
clock timezone CST -6
clock summer-time CST recurring
!
ip subnet-zero
ip domain-name cisco.com
ip name-server 172.22.53.210
ip name-server 171.69.2.133
ip name-server 171.69.2.132
ip name-server 171.69.11.48
!
isdn switch-type primary-5ess
isdn voice-call-failure 0
!
controller T1 1/0/0
 framing esf
 linecode b8zs
 pri-group timeslots 1-24 nfas_d primary nfas_interface 1 nfas_group 1
 description PacBell 3241933
!
controller T1 1/0/1
 framing esf
 linecode b8zs
 pri-group timeslots 1-24 nfas_d backup nfas_interface 2 nfas_group 1
 description PacBell 3241933
!
interface Loopback0
 ip address 172.21.10.1 255.255.255.255
!
interface FastEthernet0/0/0
 ip address 172.21.101.20 255.255.255.0
 half-duplex
!
interface Serial1/0/0:23
 no ip address
 ip mroute-cache
 isdn switch-type primary-5ess
 isdn incoming-voice modem
 no cdp enable
!
interface Group-Async0
 no ip address
 group-range 1/2/00 1/3/143
!
router eigrp 1
 network 172.21.0.0
 no eigrp log-neighbor-changes
!
ip classless
ip route 0.0.0.0 0.0.0.0 172.21.101.1

ip http server

ip http authentication aaa
!
snmp-server engineID local 0000000902000030F2F51400
snmp-server community 5urf5h0p RO
snmp-server community 5crapmeta1 RW
snmp-server community SNMPv1 view v1default RO

The following example shows configuration of a POTS dial peer with the primary controller of an NFAS group:

dial-peer voice 35 pots
		incoming called-number 45...
destination-pattern 35...
direct-inward-dial
port 1/0/0:D
prefix 35

The following example reenables the entire PRI after it was disabled:

isdn service dsl 0 b-channel 0 state 0