Which Cisco 79??. It could be a later model, which you could flash it so as to use SIP.

Anyway, try the below:

1. Download and install sccp, Chan_SCCP.

cd /usr/src

wget https://www.atken.eu/voip/v3.1.zip

unzip v3.1.zip

cd to the directory created

./configure

make

make install

2.If there is no TFTP server on your pbx, please do install (it exists on elastix).

3.Edit and update the file /etc/asterisk/modules.conf:

noload => chan_skinny.so

load => chan_sccp.so

4.Disable sieve on ASTERISK, since it uses port 2000.

vi /etc/cyrus.conf

# UNIX sockets start with a slash and are put into /var/lib/imap/sockets

SERVICES {

# add or remove based on preferences

imap cmd=»imapd» listen=»imap» prefork=5

imaps cmd=»imapd -s» listen=»imaps» prefork=1

pop3 cmd=»pop3d» listen=»pop3″ prefork=3

pop3s cmd=»pop3d -s» listen=»pop3s» prefork=1

#sieve cmd=»timsieved» listen=»sieve» prefork=0

5.Create the files OS79XX.TXT, XMLDefault.cnf.xml and SEP<MAC>.cnf.xml (where <MAC> is the MAC address of the phone), using the below contents. The files must be in /tftpboot/ or inside the directory that TFT server uses.

OS79XX.TXT:

It contains the phone firmware. It is different for each model. The below is for 7910.

cd /tftpboot/

[root@pbx tftpboot]# cat OS79XX.TXT

P00405000700.bin #The files P00405000700.bin and P00405000700.sbn should be in /tftpboot/.

XMLDefault.cnf.xml:

[root@pbx tftpboot]# cat XMLDefault.cnf.xml

<Default>
<callManagerGroup>
<members>
<member priority=”0″>
<callManager>
<ports>
<ethernetPhonePort>2000</ethernetPhonePort>
</ports>
<processNodeName>ASTERISK IP</processNodeName>
</callManager>
</member>
</members>
</callManagerGroup>
<loadInformation6 model=»IP Phone 7910″>P00405000700</loadInformation6> #Change this, based on your Cisco model!
</Default>

SEP0004C1C69651.cnf.xml #Change this MAC 0004C1C69651 with the one located on the back of your phone.

[root@pbx tftpboot]# cat SEP0004C1C69651.cnf.xml

<device>
<devicePool>
<dateTimeSetting>
<dateTemplate>DMY</dateTemplate>
<timeZone>W. Europe Standard/Daylight Time</timeZone>
<ntps>
<ntp>
<name>193.92.150.3</name>
<ntpMode>Unicast</ntpMode>
</ntp>
</ntps>
</dateTimeSetting>
<callManagerGroup>
<members>
<member priority=”0″>
<callManager>
<ports>
<ethernetPhonePort>2000</ethernetPhonePort>
</ports>
<processNodeName>ASTERISK IP</processNodeName>
</callManager>
</member>
</members>
</callManagerGroup>
</devicePool>
<versionStamp>{Jan 01 2005 00:00:00}</versionStamp>
<loadInformation>P00405000700</loadInformation> #Change this, based on your Cisco model!
<userLocale>
<name>English_United_States</name>
<langCode>en</langCode>
</userLocale>
<networkLocale>United_States</networkLocale>
<idleTimeout>0</idleTimeout>
</device>

SCCP.conf:

[root@pbx asterisk]# cat /etc/asterisk/sccp.conf

[general]
servername = SCCP
keepalive = 60
debug = 1
context = from-internal
dateformat = M.D.YA
bindaddr = 192.168.100.253 # Asterisk IP
port = 2000
disallow = all
allow = ulaw
allow = alaw
firstdigittimeout = 16
digittimeout = 5
autoanswer_ring_time = 1
autoanswer_tone = 0x32
remotehangup_tone = 0x32
transfer_tone = 0
transfer_on_hangup = on
callwaiting_tone = 0x2d
musicclass=default
language=en
deny=0.0.0.0/0.0.0.0
permit = 192.168.100.0/255.255.255.0
nat = on
dndFeature = on
sccp_tos = 0x68
sccp_cos = 4
audio_tos = 0xB8
audio_cos = 6
video_tos = 0x88
video_cos = 5
echocancel = on
silencesuppression = off
private = on
callanswerorder = oldestfirst
directed_pickup_modeanswer = on

[SEP002155D575D0] # Cisco IP Phone MAC
type = device
devicetype = 7961 # Device Number
description = 115 # Extension Number
button = line, 115, default
button = line, 111

[115] # Extension Number
type = line
mailbox = 115@from-internal
label = 115 # Name to appear
cid_num = 115
context = from-internal

*On bold everything requires changing.

On your ASTERISK PBX create a new extension as OTHER (Custom Device)! On dial field add SCCP/XXX, where XXX is the User Extension. For the above example, it would be SCCP/1.

Restart ASTERISK & Cisco IP Phone!

Good luck, since it is a big procedure.