Difference in phone boot up process : Type A vs B

[nirmalissac]

Hi All,

Type A phones : 7940, 7960, 7905, 7912 ....

Type B phones: 7941, 7961, 7945, 7965, 7970 ....

New Gen Phones: 8961, 9951, 9971....

All documents talk about generic phone boot up process in detail, but it would be great if someone can point out the higher level differences in the boot up process between the different generations of phones, if any.

One difference I noticed is, Type A phones go for XMLDefault.cnf.xml file, whereas type B phones go for SEPDefault.cnf and SIPDefault.cnf files.

[Manish Gogna]

Hi Nirmal,

There are primarily three types of protocols that involved in the  phone startup process in the models listed above, they are Skinny, SIP  and TFTP. The initial part of obtaining power, learning VLAN and  requesting for IP through DHCP is the same. Since you already have all  types of phones, you can take a packet capture using wireshark from  three phones ( one from each type ). Then filter the capture using  Skinny, SIP and TFTP. It will be the best way to check the differences  among all three types of phone models as you will be able to see the  communication between the phone and CUCM step by step with relevant  messages only.

There would be a small difference in the phones  registered with cucm version prior to 8.x and the ones on 8.x and above.  You will see a request for an ITL file in case of 8.x and above because  of the SBD feature.

A good reference doc for SCCP and SIP registration

https://supportforums.cisco.com/docs/DOC-21496

HTH

Manish

[nirmalissac]

Manish,

Thanks alot for your time .. i have only Type A phone with me.. i will try to arrange a type B phone n check using wireshark...

[Manish Gogna]

Hi Nirmal,

Good to know that it helped. Don't forget to rate useful posts and mark the post as solved to help improve supportforums.

Manish

[nirmalissac]

  ... anyways i didnt mark it as solved coz, i thought someone may post in this thread with their ideas as I do not have a type B phone to verify the same..

[Manish Gogna]

I'll try to get the sample captures for you on Monday if no one else posts it before that.

Manish

[nirmalissac]

Thanks a lot bro

[Manish Gogna · Accepted solution]

Hi Nirmal,

Please check the attached pcap for a 7975, filter using 'Skinny' and 'TFTP' to see major diff compared to other models, plus you will also see the ITL file request in this pcap.

HTH

Manish

[nirmalissac]

Thank you soooooo much bro. I will analyse the capture and post the findings .. your help is highly appreciated...

[nirmalissac]

Manish,

I do not see any differences in the boot up process. In this pcap, the phone downloaded config file and registered. I think SEPDefault.cnf and SIPDefault.cnf are used when the phone goes into auto registration mode.

Anyways, thanks a lot bro