Very good document. I have a question.

In the attach accept message, the IP address allocated to UE is mandatory. However, there is no DNS related information. I checked spec, in the PCO (protocol configuration options) DNS server address can be included. However PCO is optional. So I just wonder, without DNS server in PCO, how could UE access the internet?

Hi, Did you find the answer anywhere ? 

Hi Netmania ,

Can you please clarify points put by fanrui. Thanks in advance.

Hello,

Normally, DNS server address is always included in PCO. If not, UE is only able to access internet using IPs (no DNS server to translate the domain, etc.) or manually defining the DNS server in the UE.

Hi Netmanias,

                   First i have to thank you ,that you shred a very valuable document with us regarding lte stuffs , but here i have one small suggestion , in point of initial attach part-1 &2 ,document maily focusing on core network rather on RRC messages (i.e., between UE and Enodeb).can you please add one more document(which highlits UE and Enodeb messages and transcations) related also,so that end-to-end connection would be clear for us.

Thanks,

Nagarjuna.

Hi Netmanias,

Really appreciate the depth of the information provided. Can you please also add "Selection of MME" in the eNodeB (using static/DNS queried)?

Very Excellent！Thanks for your sharing! I have got lot of information about my concern topic.

Thanks for the detailed explanation. Appriciate to have a thought to share the knowledge like this...

Man, congratulations and thank you

Really Really Super. Thanks Guys

Glad you liked it. And thank you for your interest!

Stay tuned!

Great explanation! Thank you very much.
 

Good explanation!!

good explanation and  well explained in main areas of call flows

There is typo in "Figure 7. Procedure for EPS Session Establishment (1)" step 14 : "Receive S5 TEID (DL)" should be "Receive S5 TEID (UL)".

yes corrrect

I was thinking same as you. Thank you for notice so I know i wasn't wrong.

Above all - good explanation

Can somebody help me with the softwares required in this simulation?

hi everyone,

Is it possible to establish more than 1 default bearers? I mean within an initial attach procedure the EPS can setup more than one APN default bearers for example one for internet and other one is IMS bearers? Or only one default bearer can be setup within an initial attach procedures and other additional default bearers can be setup upon demanded?

thanks for your supports.

Hi,

Thanks for such nice explaination.

I have one doubt.why HSS Generate more than one AV(Authentication Vector) for single UE?

Yes i've the same doubt. Someone clarify it

Hi , 

Good explanation . 

I have one question , i got a lot of Attach rejection and when i checked ,all  are related to the case when Attach complete were not sent to the MME .

How can we analyse this issue ? 

I am using Astellia 

thanks. 

Hi,

In Step 14, Should'nt it be ReceiveS5 TEID (UL) instead of Receive S5 TEID (DL) on the S-GW ? Or did i miss something :/

Hi,

Great Explanation, Thank You for taking the time to document in such great detail. 

I have one question regarding MSISDN, With reference to Fig 7. Create Session Request, will MSISDN be exchanged between SGW and PGW?

One more thing will IMSI be always included in the create session request message?

Thank you for all your help

diy

yes IMSI will be present in CSR

yes IMSI will be present in CSR

Yes MSISDN is found in ULA and CSR

Hii ,

      If I want to make a volte call ,will this lte authentication happens first before going to ims part?

Hi Chaitu,

Yes. UE(device) LTE authentication happens first, once UE gets IP Address then IMS Registration( authentication) happens.

regards

Saravanan.

Thabk you for the detailed explanation!

Can you please explain what NAS-MAC is ?

Hi Folks,

Could someone please explain, how internet connectivity is established in UE? I'm looking for that sepecific message (RRC/ NAS) which upon receiving establishes a successfull internet access. Like if look at the smartphone, there should be up and down arrow at the signal range icon. Please see the attached image. So when will this happen or which message establishes this internet connection? Please help.

Hi Netmanias,

Could you please explain the CSFB call flow ?

thanks,

Anis

I Have A Quary, when UE first time attaching with the network, how it get LAI in 3G and tAI in 4G.?????

Is it possible to establish more than 1 default bearers? 

Hi,

Thanks for such nice explaination.

I have one doubt.why HSS Generate more than one 

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Hi Netmanias,

After step 29 there should be step 30 but it is mistakenly written as 39.

Also, in the same step, the E-RAB Setup Response is shown between e-Nb and S-GW, but it should be between e-nb and MME.

Kindly acknowledge.

Overall, this website is loaded with detailed diagrams and descriptions of mobile cellular protocols. Thanks for the major effort in providing free access to this treasure trove!