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Can anyone explain how Triple play services work?

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18 years 3 months ago #16148 by taqqi14
Hello !
I wana grasp the concept of Triple play services in which internet,telephone and Tv services are offered on a single line (either fiber or coax ).I know the basic concept but wana learn how is it done in detail.How traffic from 3 headends are transmitted to home?network diag would be appreciated .And what is the role of MPLS in triple play .
Thnx

Rgds
Shahzad
Taqqi
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18 years 3 months ago #16150 by Ranger24
Hi,

Read the DSLAM Basics thread in the Basic Concepts forum as this provides details of network architecture required to deliver Triple Play services to Residential or Business customers.

Having said that there are many ways to deliver the 3 services and still call it triple play i.e Voice via PSTN, TV via Satellite, and internet via DSL.

R

And maybe this thread should be moved to basic concepts...Moderators?


Patience - the last reserve of the any engineer
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18 years 3 months ago #16153 by taqqi14
yup i read it but doesnt include Tv service .If anyone can help me guide how tv,phone and internet signals can be transmitted to a single fiber or coax medium.
I agree this post shuld b on basic concepts section.sorrry about tht

Rgds
Taqqi14
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18 years 3 months ago #16155 by Ranger24
Hi,

TV services require a Head-end to be present and connected to the network, typically at the same level as the WWW gateway.

At the customer side there needs to be an IGMP based Set top box, so we end up with the following network:

TV --> STB --> CPE --> DSLAM --[MetroNet]-- BRAS --> Headend

The process should work as follows:

1) Customer A selects channel 1

2) STB recieved request for channel 1, and creates the correct IGMP Join message.

3) STB send the IGMP JOIN upstream to the DSLAM

Now we have 2 different scenarios:- IGMP Aware DSLAM or IGMP Ignorant DSLAM. Lets Look at the IGMP aware DSLAM first:

4) DSLAM Intercepts IGMP JOIN Message and forwards as unicast message to Head End via BRAS.

5) BRAS forwards IGMP JOIN to Head End

6) Head end recieves Join message and streams channel to DSLAM.

7) DSLAM recieves channel and streams to customer A.

Now lets's assume a second customer requests channel 1:

1) Customer1) Customer A selects channel 1

2) STB recieved request for channel 1, and creates the correct IGMP Join message.

3) STB send the IGMP JOIN upstream to the DSLAM

4) AS the DSLAM is IGMP Aware it should firstly check to see which channels it is recieving, and as it is currently recieving channel 1 the DSLAM should connect Customer B to channel 1 straight away.

5) Should the head end send and IGMP membership query messages the DSLAM should respond as a member until the last customer has stopped watching the channel.

If the DSLAM is IGMP ignorant then the channels are always streamed from the headend. This means if 5 customers watch the same channel the DSLAM recieves the same channel 5 times, thus increasing the bandwidth demands on the entire network.

Questions?

R


Patience - the last reserve of the any engineer
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18 years 3 months ago #16164 by taqqi14
Thnx for a very comprehensive explaination.it cleared the basic concept.Can you recommend any vendor specific detail such as which STB ,Dslam and Bras to be used?
And if DSLAM is not IGMP aware how can there still be one stream for every customer tuning into a single channel(lets say cnn).?
Whts the role of MPLS in this kinda network and how Headends are terminated to a device (CMTS may b) ?can anyother device (other than CMTS) b used to terminate 3 headends?does one device b able to terminate all 3 TV,phone n internet headends ?

Rgds
taqqi14
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18 years 3 months ago #16178 by Ranger24
Hi,

When it comes to product recommendations I can only go with what I know:

DSLAM - Nokia D500. The worlds first true IP DSLAM (12 months anead of market leaders alcatel...who still haven't got there completely IMHO). Advantages of the Nokia:

1. Design: It uses a single contral card for the IP/ethernet upstream connections whereas a large number of other 'IP' DSLAMS are really an ATM DSLAM with a IP Blade added - bad news for latency sensitive applications like IPTV.

2. Has an analogue POTS (Plain Ordinary Telephone System) line card allowing vendors to offer VOIP based telephony to customers without them having to change their phone. The D500 converts the standard analogue phone conversation to IP and uses SIP for the VoIP Signalling.

BRAS - I'm going to recommend the REDBACK SmartEdge 400/800 routers. Quite simply these are the best edge routers in the world. (Sorry cisco fans - Firewall please don't ban me!) Our cisco team load tested the SE against Cisco 7500 series edge router to the point where the router gave up. Once overloaded the ciso took 20 minutes to recover, where as the Redback took 5 minutes - Thats a lot of revenue saved when every minute downtime can potentially cost hundreds of thousands pounds / euros / whatevers. Further to this the router architecture is such that should you lose the main control processors you do not lose traffic.

They also have a system of 'contexts'. each context is a virtual router within the SE. This means the basic port settings can be applied system wide, but different traffic type can be dealt with by seperate context..simplyfies traffic management and improves flexibility[/b]

STB - less experiance here. Only used PACE (based in UK) work okay and no major complaints.

As for your other questions:

If DSLAM is not IGMP aware how can there still be one stream for every customer tuning into a single channel(lets say cnn).?

Simpley but expensive - the only way i can think to do this is ensure the next hop from the DSLAM is a router acting as an IGMP proxy.

Headends

I'll be honest not really my field of expertise but the headend site could contain the equipment for all three services - Softswich for Voice (SIP or H.248 based), TV broadcasting kit / multicast servers, and Internet Gateway servers/routers.

MPLS
Not my area...sorry. I'll look into it an if I find answers post them here.

and 1 question from me to you...CMTS????

hope this helps, and remember my product recommendations are highly biased!

R


Patience - the last reserve of the any engineer
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