Saturday 31 October 2015

Do I need a NAS for my home network

Our world is increasingly digital. We generate a lot of digital content (photos, videos, personal documents, purchased music & videos, etc) as opposed to what we did 10 years ago. Overtime this keeps on growing as many of them are related to memories and no one wants to delete memories. Plus you have digital documents and other assets that you simply cannot lose ... 

Previously we had all these user generated content in hard-copies (film negatives and positives), cassettes/DVDs, etc all of which are perishable material. Today no one lies to print all his photos or archive data in tapes and CDs. rather people prefer to keep all their data in a redundant fail-safe storage which is accessible from all kinds of devices (tablets, smartphones, computers, TV STB), possibly even from inside and outside his home at any time of day, week, month or year. And you cannot keep all of this data on Google Drive, One Drive, Dropbox, etc ...

All computers, hard disks, pen-drives, CD/DVD media fail at times. You should not be trusting a single copy of your data to be always available.  Should you do that  and some failure happens, you know what misfortune you are bringing upon yourself. This is where NAS (or personal cloud storage) comes in. A good NAS should provide N:1 redundancy (where N=1, 2, 3 ...) so that essentially in the event of mechanical failure, your data is most likely safe. You get diskless NAS models to 2/4 bay diskless or ready to store models in market as well as you can recycle old computers to build FreeNAS based file servers (I use this).  So by all means go ahead and get one which suits your need, pocket and skill level.


- Suman Kumar Luthra @ APRC-P3 Telecom Sub-Committtee

Friday 30 October 2015

Do I need to run optical fiber to all data locations with eye on future ?

No. Fiber is rumored to have almost infinite bandwidth and possibly that's what starts this question. 

Fiber Optics is used for long range communications where low voltage electrical signals (like those that go on LAN or cat6 /6a cabling) cannot propagate ore lengths beyond 100m. This scenario is not faced in almost all homes of this project. Fiber also cannot supply power to PoE style devices. And cat6  speeds are common at 1 GbE (just as Fiber) with 10GbE on the horizon (it will require extremely expensive equipment to support such speeds on optical fiber).  On a per port basis optical fiber maybe 10 times expensive than LAN with little or no support on home devices and appliances. 

From a user perspective, its very hard for any home user to fully saturate the 1 GbE link bandwidth of cat 6/6a and these ca6/6a can support 10 GbE in future. So the use cases of "infinite bandwidth" are non-existent now in the home (and possibly in the 10 year period too). it can also handle any high-speed broadband service (10 Gbps) for the next 10 years in India. We are just stuck at 100 mbps at the premium end mostly with realistic E2E max throughput not exceeding 25 mbps,

Some Home automation firms push  fiber optic cabling in home as a means to carry 4K and 3D or higher video resolutions, but the cat6 infra is more than sufficient to handle that too.

So its a nice science  project to run fiber to each device and play around,  but that's what it really is. No practical use.


- Suman Kumar Luthra @ APRC-P3 Telecom Sub-Committtee

Thursday 29 October 2015

What is the future of WiFi technology and how can we be ready for future ?

Currently Wifi is using IEEE 802.11ac which uses 5 Ghz band and also supports legacy 2.4 GHz band clients. In terms of antenna, routers with 8 antennas (4x4) and direction beam forming and client bandwidth/priority allocation are inn the market. Their is a proposal to develop a router with 16 antennas (8x8 MIMO). Some routers support two or three 5 Ghz bands and one 2.4 Ghz bands. However this is just an implementation strategy with little or no  benefits on a per client basis but just increases the overall capacity of router to handle more clients each able to work at possibly much lower link speed than what speed label you see on the box. Of-course many homes may just do fine with this.

Technology wise the Standard work is happening on Gigabit Wifi (802.11ad or WiGig) as well as competing WirelessHD. Both these standards use the 60 Ghz band. One important consequence of this (by design to escape interference) is range of Wireless signals is further limited. 5 GHz range is less than 2.4 Ghz and 60 Ghz will be much less, possibly the size of the room and may not be able to penetrate concrete walls.



So the future of High Speed Wireless LAN is most likely "Multiple Access Points/Routers" in one home, probably one per room and supported by an underlying Wired Gigabit Ethernet LAN to hook up each room to the router in a broadband entry location.  Of course for this to take root all clients also need to change (for 60 Ghz frequency support) and that may take a long time(5+ years) to materialize with intermediate implementations supporting all 3 bands (2.4, 5 and 60 Ghz bands)

This is ONE MORE reason on why we insists that every room have Wired LAN connectivity by at-least having one LAN Port in every room and having structured cat 6/6a wiring.


- Suman Kumar Luthra @ APRC-P3 Telecom Sub-Committee


Wednesday 28 October 2015

Should i use 2.4 Ghz or 5 Ghz frequency band ?

Network Gear Situation:
With respect to frequency bands (or wireless carrier), Router are classified as:

  1. Single band - Will support only 2.4 Ghz band (entry level)
  2. Legacy Dual band - Will support both 2.4 Ghz and 5 Ghz but only one at a time
  3. Dual band - Simultaneously operate both the frequency bands
  4. Tri-band - Will support TWO 5 Ghz bands and ONE 2.4 Ghz band

Each frequency band means a virtual logical router in itself with independent SSID (Wireless network name)

A client will support either 2.4 ghz or 5 Ghz at a time. Never both simultaneously even though it cant support booth the frequency bands. And a lot of legacy Wifi clients or simple devices uses 2.4 Ghz only with only the latest ones being able to support the 5Ghz band additionally.


Tradeoffs:
  1. 2.4 Ghz has more range (will reach father from router/AP) but will suffer more from interference with neighbor's network. 
  2. 2.4 Ghz has more client support (and therefore more ubiquitous)
  3. 5Ghz has less range and faces less interference from neighbor's network
  4. 5Ghz has fewer client support (only modern devices). 
  5. 5Ghz suffers more attenuation from walls and household objects and performance falls drastically outside the room where AP/router is placed. 
  6. 5Ghz has more channels and more bandwidth compared to 2.4 Ghz

Here's a reference graphic comparison:




Which will give better throughput ?
Hard to verdict with 100% confidence. It depends on what factor dominates a deployment scene. Generally if we get a good signal strength, it will be the 5 Ghz band (less interface, more bandwidth). But this changes from home to home. If signal crosses more walls, 5 Ghz range dramatically falls and makes it unusable and worse than 2.4 Ghz.

It should be clear why I hate Wifi. To many ifs and buts ...


- Suman Kumar Luthra @ APRC-P3 Telecom Sub-Committee

Tuesday 27 October 2015

Can you practically illustrate the interference problem ?

Please take the following as one reference Multi-Dwelling-Unit (MDU or apartment complex) example of the unlicensed 2.4 Ghz and 5 Ghz spectrum usage (from my current residence):

























The figure on the left shows the 2.4 Ghz spectrum usage while the figure on the right shows the 5 Ghz spectrum usage (with my 5 Ghz AP only). It should be clear that the 2.4 Ghz band is congested while the 5 Ghz is empty and free for my outdoor AP use.

The results I got are like this:

  1. My 2.4 GHz AP gives best case (client  device right over antenna) of around 40-45 Mbps while the 5 Ghz AP gives best case result of 90-95 mbps. A factor of two in the ideal case
  2. In longer range, I could extract a performance of max. 7-8 mbps from the 2.4 Ghz Outdoor AP while the 5.0 Ghz AP gave me results of 15-16 Mbps. A factor of two again. I had line of sight between client device and and AP with only an occasional tree and leaves as obstacle. 

The interference problem is particularly severe in apartments because of the density of flats (and each has a wifi routers). If we go to a villa or large bungalow community, the problem is less severe.

Please note that the 5 Ghz  suffers great attenuation from walls and based on that the results could change the other way round. But the above case clearly demonstrates quantitatively the impact of interference when both the 2.4 Ghz and 5 Ghz APs are theoretically rated to be able to do the same speeds.

- Suman Kumar Luthra @ APRC-P3 Telecom Sub-Committee

Monday 26 October 2015

Can I have two Broadband connection simultaneously in my home network ?

Yes you can. I assume you want two broadband network simultaneously serving one home LAN network.

This is very uncommon in home environment, where typically each home has ONE broadband connection serving one home network, but is very very common in enterprise network where two or more branch offices are linked to each other via separate broadband connections or leased lines for redundancy and fault tolerance. Various schemes exist to use these broadband connection like 50:50, round robin, active-standby and so on, Perhaps one of these schemes is what you may be looking at while trying to use more than one broadband connection at home.

So all we need to support this requirement is to port an entry-level enterprise solution in the home environment. This involves incorporating a wired load balancing router (3-8 ports) or using a Wifi Router that supports dual WAN. These routers substitute the existing wired or wifi router at home without disturbing the home network architecture in a major way.

Wired load balancing routers, however, in terms of configuration, is quite different (rather complex) from your regular wireless router which actually is a two port (or two interface router)+ integrated 4-port LAN switch where one interface connects to one internet connection (WAN) and the other serves the LAN over wired and wireless. And the wired load balancing router solution is not limited to two internet connections, but can use 3, 4, 5 etc depending on how many ports (minus 1) that the load balancing router has.



DataFlow (Router with 2 WAN and 1 LAN)


Physical Network interconnection topology


Various solutions exist to serve consumer level load balancing router market like:

  1. Ubiquiti Edgerouter Lite ER3 (https://www.ubnt.com/edgemax/edgerouter-lite/) - I use this as my router at home. 
  2. TP-Link TL-R480T+ (http://www.tp-link.com/en/products/details/cat-4910_TL-R480T%2B.html)
  3. Draytek Vigor2925 (http://www.draytek.com/index.php?option=com_k2&view=item&id=5247&Itemid=660&lang=en)
  4. Trendnet 4-port dual WAN VPN router (http://www.trendnet.com/products/proddetail?prod=185_TW100-BRV324)
  5. Some  Wifi Router like  very popular and common Asus RT-AC68U in which you can configure one of the 4 LAN ports or the USB port for failover/load-balance of wifi [http://www.techpoy.com/2014/11/asus-rt-ac68u-dual-wan-set-up.html]

and these are frequently used in home environments and small home offices.  You may see more suitable candidates from the router rankings at smallnetbuilder:

http://www.smallnetbuilder.com/tools/rankers/router/ranking/None/rev8/6

One typical use case is work from home (or even Virtual Desktop) which requires a stable link. the two connections will provide you more reliability and fault tolerance in your link with office (It should be more rare for two broadband connections from different SP to go down at the same time). The principle is same as that of core reliability design i..e of using redundant unreliable parts to make the system more reliable.

However if you are using Home office, you may want to keep home network and office network separate physically by just keeping two connections, two ISP modems and two routers. 


- Suman Kumar Luthra @ APRC-P3 Telecom Sub-committee


Sunday 25 October 2015

How exactly can a load balancing router improve the performance & reliability of consumer broadband connections ?

A broadband connection can encounter a networking or cable fault anywhere within the campus or outside (fiber or cable damage outside APR) which is beyond the control of any subscriber. If it happens it may take a day (or more) also to fix at times. If you think you have a critical requirement like work-from-home which you cannot afford to compromise on, then its is better to dedicate a secondary backup internet connection. Their are three types of policies that are typically used with load balancing routers:

Case 1 - Active Standby Model


Here one of your connections is always designated as the primary (It could be a fast FTTH connection) while the secondary is designated as secondary (It could be slower and cheaper ADSL, 3G/4G Mobile Broadband or just a cheaper FTTH connection). We expect the fault in the primary connection to be intermittent and random and this topology will help overcome the temporary outage. And the transitions are transparent to the user (i.e. handled entirely by the LB router)


Case 2 - Round Robin Load balancing

This can be used if your primary connection is unreliable. In this case you can buy two high speed connections and load balance round robin (weighted or unweighted) through them If one of them goes down, your application still work through the backup without any observable degradation in performance. This is very popular in enterprise environment to connect two branch offices or by data centers.

Another use case is to increase Internet speed. The max speed at APR is now 100 mbps (supported by both Airtel and ACT). Let say you want a 200 mbps connection for some reason (including bragging rights). This will satisfy your need (but make sure you have a GbE router not fast Ethernet one)  You can add another 50 Mbps using Pursuit Edigital Internet service a LB router with 3 WAN ports if that's what you are after ;-))


Case 3 - On Demand

If you ISP supports 40 Mbps and 100 Mbps connection speeds but not 60 Mbps, then this is what you can go for. Use the 40 mbps connection as primary and another 20 Mbps from other Service provider, then the 2nd interface can be used if the first hits its peak speed. Maybe especially attractive if you have a good plan on pay per use on the secondary connection.

In the interest of Reliability and network fault tolerance, I do not recommend taking two connection from same ISP. Its very rare that only your one connection will go down. Generally a network fault (more common) will impact an entire complex or area for a particular ISP. So if you take both connection from same ISP, you may find that both yor connections are down together at same time defeating the reliability requirement entirely and frequently.


- Suman Kumar Luthra @ APRC-P3 Telecom Sub-Committee

Saturday 24 October 2015

Can a Load balancing Router help do some static host or service based load balancing ?

Depending on the model of the load balancing router you use, you may be able to statically partition your hosts and your applications to use a specific internet connection. Please check the feature list and/or configuration guide of your router 

For eg., you can always make a router use a specific service use a specific connection. For eg., you may have both ACT and Airtel connections, with BitTorrent, Tele-presence & videoconferencing applications use th ACT connections (uploads are not counted), but other applications continue to use the Airtel Connection. 



You may also use such routers to partition your WEAN (internet hosts) which are only accessed using specific connections.  For eg., you have 10 GB free Airtel Wynk data on Airtel BB connection and so you want all wynk access to go only through the Airtel connection (irrespective of client device) , while other applications can use either Airtel or ACT connection. 



The following is an enterprise diagram. You can partition your LAN network into segment s like CCTV, office device, personal devices, kids devices, wife's devices and so on and make them use specific connections.



- Suman Kumar Luthra @ APRC-P3 Telecom Sub-Committee

Friday 23 October 2015

Can we extend our home WiFi Network beyond our apartment indoor area ?

Very much. Wifi works in unlicensed and unregulated spectrum bands (2.4 Ghz, 5 Ghz and 60 Ghz in future). This part of spectrum is free for use. Nobody owns it and therefore you are legally free to extend the range of your home Wifi beyond the closed range of your apartment.

The common use cases for outdoor wifi are:

(1) You live in ground floor and  have big courtyard/garden/backyard where you spend quite a good amount of time and would like to browse while sitting on iPad/Smartphone/laptop/Gaming console.
(2) You live in a penthouse and you need a very strong signal outdoor in your terrace area for same purpose as above
(3) You live anywhere in middle floors, but you sit, walk and spend a lot of time in the common area in-front of your apartment and would  like to have your Wifi to reach there.
(4) Or simply want to set a free hotspot for community or guests.

So in order to extend your home wifi network, pick up a simple Outdoor Wifi AP (these are weather and dust proof, mostly powered by PoE) unit like:

(a) Ubiquiti (Loco) M2 or M5
(b) Tp-Link Outdoor Wifi AP (2.4 and 5 Ghz versions)
(c) or any other similar equipment

which features directional antennas and mount it in the balcony area facing the area which you want to cover (the signal will spread in a cone). The range will depend on the antenna Gain characteristics. Depending on the interference, distance and Line Of Sight between client device and AP, you may be able to get your entire Internet Speed (upto 100 mbps for 802.11n 5 Ghz band) at the outdoor location covered by the signal cone. For terrace or private garden/backyard, you may even use outdoor APs with omni-directional antennas as the area to be covered is small. The signal will not be able to penetrate thick walls and come oput on other side. So if you have a building in-front of your flat, do not expect the signal to penetrate and be strong or even visible on the other side of the building.

Both the ubiquity and Tp-link units are priced in the Rs. 3000-4500 range and therefor are not an expensive investment to make/trial out. Personally I have tested Ubiquiti Loco M2 and M5 models  in LOS conditions upto 50-70m from my 6th floor apartment and am specially happy with the Loco m5 performance.

Infrastructure wise, you would need a LAN port at the outdoor mounting location in balcony/terrace and this is something you should have planned for in advance (or have to do modification otherwise). It is very rare to have planned for a LAN port in balcony/utility/terrace etc in advance though.

- Suman Kumar Luthra @ APRC-P3 Telecom Sub-Committtee

Thursday 22 October 2015

How to do telephone wiring Inside our home ?

Data cabling works only in one wiring topology i.e. STAR with the switch at the STAR point. However the STAR is not the only option for telephone wiring. Their are others like Ring, Bus, or some hybrid. For brief intro on these typologies, refer the following web-page

http://www.homephonewiring.com/route.html

Most builders (including ours) by default provide Bus topology (the likely motive  being to save cable , conduit and labour cost and effort). However telephone cables are rather inexpensive, conduits are one time investment for each home and therefore we recommend that in the interest of maximum flexibility and ability to add new points without disturbing existing ones, all owners go for STAR wiring only (i.e. REDO the telephone cabling). In-fact telephone cables are thin and can share conduits to each room used by data or coaxial cables, safely. With STAR topology you can keep multiple handsets and multiple landline connections too with the interconnect done at the star point.

We do not recommend using telephone cables out of data points as they reduce data port speed to 100 mbps max (from 1 or 10 Gbps) and also each such sharing port loses ability to do PoE (both passive and active). Moreover high voltages(incl. short risks) are used at times to ring phones and it stands a chance of interfering with even the 100 mbps speed data traffic. However you can use separate Cat 5 cables (cat 5e/6 is overkill and waste of money) as telephone wires (they use twisted pairs and offer better protection against electrical interference) compared to straight-pair telephone cables (infact this is the new recommended standard for telephone cabling). Cat 5 is also only marginally costlier than 2-pair telephone cabling and therefore an attractive preposition.


- Suman Kumar Luthra @ APRC-P3 Telecom Sub-Committtee



Wednesday 21 October 2015

And how we handle Cable TV wiring ?

In general the use of coaxial cable is declining worldwide in favour of Optical Fiber for Internet and TV signal distribution outside the home and Ethernet (Cat5e/6) inside the home. . Even analog CCTV cameras are getting replaced by digital. 

However because most Setop boxes and TV still expect a coax Input and as such we need coax cable from ONT/ONU to STB. In india still TV distribution by Optical fiber is not widespread and DTH/Traditional cable TV networks hold sway due to which we must be prepared to install proper coax wiring for the next 5-10 years for Video (TV).

Again like Ethernet and telephone, coaxial wiring must be done in a "STAR" fashion and not "Bus" Topology by using splitters, in case of multi TV configurations. It is recommended to install either


  1. an inline signal amplifier + splitter or
  2. a multi-channel switch (non-cascading)

at the STAR point if splitting is done to serve more than 1 TV.

Generally one should make a provision for TV in every room, and hence this may be unavoidable to maintain signal strength. It is also recommended to run 3 cables to each access point from the STAR as many STBs feature dual Tuners, pl;us we may need the ability to receive both terrestrial radio/tv or local Cable TV in addition to  DTH transmission. This is a one time investment.

Also RG6 is the recommended cable TV/DTH coaxial wiring standard (costs Rs. 10-12/m in bulk package in India). However we recommend that "RG6/U quad shielded cable ore RG6QS" (Rs. 40-50 per meter) be used as it offers better high frequency and EMI performance and is the new recommended standard for MATV, recommended satellite TV distribution standard in residential or commercial premises. Commscope, Finolex and Belden are the better brands (in order) of coaxial cable in Indian market (Refer http://www.broadcastandcablesat.co.in/cables-dth-and-catv-drive-demand.html)


- Suman Kumar Luthra @ APRC-P3 Telecom Sub-Committtee

Tuesday 20 October 2015

Can we use VoIP in india and how we can prepare our apartment cabling for this ?

I will answer the 2nd part of the question first because its in our hand. 

In US, their are many Over-the-top VoIP providers like Vonage, RingCentral, PhonePower, Skype, Jive, etc. Apart from these companies providing smartphone, Tablet and PC apps, they also provide fixed terminals like:


  1.  A VoIP phone - an IP Phone usually powered by PoE ( made by Cisco, Linksys, Grandstream, Polycom, etc). This needs a RJ45 data port at each location, and possibly, an electrical socket nearby if PoE is not feasible.
  2. An VoIP Analog telephone adapter (ATA) which usually accepts an RJ45 data port as input and has two ports for connecting regular POTS analog phone terminals

VoIP maybe delivered in OTT fashion i..e, it will come on your Broadband connection, or it can be even offered by Telco (business connection) in which case it may come like IPTV service on a separate LAN port of ONT. All you need for using such a device is a data port at the device location and the option to connect to either your home network or to the special ONT Port.

To answer the second part, please note that presently, In India,  regulatory framework is restrictive of VoIP services, possibly in order to protect the incumbent long distance voice operators from loss of STD/ISD revenue. In particular VoIP Gateways are not allowed to be put inside India to bypass STD/ISD toll. As such all foreign based VOIP server services are illegal to use in India, TRAI treats VoIP as a service different in scope, nature and kind from real-time voice as offered by Telcos and long distance carriers. However as a consequence only the following type of VoIP or Internet telephony is allowed in India:

  1. PC to PC Voip Call within or outside India
  2. PC/IP-Phone/Adapter to a landline/mobile abroad (The gateway in this case is outside India)
  3. PC/IP-Phone/Adapter connected to ISP with static IP calling similar device inside or Outside India (again an IP-IP call)

Their is also no number (E.164) allocation strategy for VoIP as given to fixed line voice, GSM or CDMA voice. ISPs are forbidden from putting E.164 to IP address mappings as recommended by IANA is forbidden. This ensures a different quality of experience than using regular landline or mobile phones. To summarize VoIP does not have a level playing field in India as in US, especially when interconnect with legacy voice networks are concerned.

Things however may change in future, but the time-frame is not determinable. Owners can however prepare infrastructure upfront as highlighted above to be ready for this eventuality.

UPDATE October 2018: The Indian Government has relaxed regulations (6 months back) allowing the use of VoIP or Wifi by all Telecom services license holders (their own or other providers's network). As such both VoWifi/Wifi-Calling and VoIP are now feasible in India if launched by a telecom license holder like BSNL, Bharti, Tata, Vodafone, Idea or Reliance. BSNL WINGS is now the first usable VoIP service in India with seamless connectivity to all landlines and mobiles and works on any Wifi and any Cellular bearer /transport technology. 


- Suman Kumar Luthra @ APRC-P3 Telecom Sub-committee

Monday 19 October 2015

So can i use Vonage, Skype, Whatsapp, Viber and other OTT VoIP services in India ?

VoIP is permitted in India subject to regulations of interconnect with landline/mobile numbers in india. So you can use these OTT services and VoIP application/device to call

  1. IP Phones in other countries
  2. Landline/mobiles in other countries.
  3. IP Phones in any part of India (provided you use IP addresses and not E.164 compliant telephone numbers)
Skype, Viber, Whatsapp, facebook messenger, etc are IP Phone to IP phone type of calling applications and therefore are perfectly legal. 

You cannot call a landline India. If you try calling a landline/mobile in India would require to connect to server outside India and then route using PSTN/PLMN gateways which will incur significant ISD charges making local and STD calling prohibitively expensive and render it un-competitive (on cost) in comparison to traditional voice service offered by telcos and cellular operators. Similarly their is no way to call a VoIP number from landline/mobile number in India.


- Suman Kumar Luthra @ APRC-P3 Telecom Sub-Committee

Sunday 18 October 2015

How many communication (RJ45, RJ11 and coax) ports I really need in my apartment ?

Their is no answer that is just right for everyone. Different apartments interiors are styled differently based on owner's need and foresight. Infrastructure investment is also a matter of initial pain and latter gain tradeoff which many owners may not be able to appreciate. Here is what I think, i am going to plan my potential port allocation at different places may be like:


Any TV Area (1 ft height) - 6 ports:
  1. IPTV STB – 1 RJ45 Nos.
  2. Internet and LAN television (n STBs but only one used at a time, n indeterminate (1-10 possibly)) – 1 RJ45 Nos.
  3. Cable Television – 3 RG6 COAX Nos. (1 for cable TV/Terrestrial radio and 2 for DTH)
  4. Smart TV Unit – 1 RJ45 Nos. ( They use this to upgrade the firmware (and use some smart features).

Any Study Table/Area/Desk (4 ft height) - 5 ports :
  1. Data – 2 RJ45 (study table (not in LR)
  2. Telephone points – 2 RJ11 (1 for Landline, 1 for intercom)
  3. VoIP Phone - 1 RJ45 POE Nos.
  4. No TV

False Ceiling in BRs, LRs, FRs and DRs - 2 ports:
  1. Wifi Access Point – 1 RJ45 PoE Nos.
  2. CCTV camera – 1 Nos. (only provision, not use for privacy or use in maid visiting hours only)
  3. No telephone or TV

That's a lot of ports in house and almost 100% owners would not have initially planned like this.  Its perfectly fine that you can assume i have started doing drugs, have lost my mind and restrict yourself to only data point per room (and distribute using small switch if required). Fact is new data point use cases emerge over time.  and individual flat resident needs are different: some people will like to go for one AP per room, while others may go for one AP for whole flat. Some may go for CCTV only in 2 points, others at more and most probably none.

Apart from my above hyperbole list, there may be other locations that need only CCTV, Only Wifi AP, Only landline, intercom and VoIP phones, etc. It can only be done with your interior work and some amount of conduit and cabling rework  is unavoidable.  We can only recommend that one be generous with conduit laying and face-plate allocation (even if no wires are drawn or ports installed) so that extension is easier down the line (no need to chip walls or expose ugly casings on the surface). Conduit design (where to use thick, where to use medium, where to use thin) plus where all to provide conduits is the most important consideration.

Cabling design - type, number can always be changed later. For eg., Its possible to use a star point in every room for RJ45 and connect it to main RJ45 STAR hub point for the flat rather than use every cable as a home run to central star point. Not every device needs 1 GbE. For eg., TVs doing 1080p, VoIP Phone, CCTV streaming needs less than 10 Mbps today. In future TVs maybe they will need 100-200 Mbps max (next 10 years).  Every such STAR point will have to have a small network switch (8 port). Similarly some cat6 can be replaced by Fiber optic cable if required 20 years down the line.


- Suman Kumar Luthra @ APRC-P3 Telecom Sub-committee

Its 2016 mid. Should we go for 10 Gb Ethernet now ?

10 GbE Ethernet is still some years away from becoming common in consumer market. The current status is that it is target towards enterprise market and therefore prices are generally high:


  1. A 10 GbE switch will cost $1500 easily and may have to be imported wheras 1 GbE switches start from $30 only
  2. A 10 GbE PCI card costs $200-$400 whereas a PCioe 2.0 GbE interface is available for $15-$20 only
  3. Cat6A cabling is difficult to procure and it costs 3 times compared to Cat 6 UTP. Connectors would similarly be expensive
  4. Their is no real time application (including 4K/3D video that would need more than 100 mbps speed. The content ecosystem is mature only for Full HD (1080p)
  5. The WAN (Internet speed) typically seen at the top end in India is 100 mbps with 1 Gbps being offered only in select cities near the sea.

Their is very little reason for consumers to want or even care about 10G in home network.  However one case is starting to emerge slowly in a small minority of very advanced home networking setups:

In some deployments, users will centralization workstation storage in a RAID-1(N) NAS and use the  PC/Laptop/Workstation as a data less client which works on fast SSDs. Typically SATA 3 buses show this type of performance profile
  • Host to Disk speed of 100-200 MB/s (0.8 to 1.6 Gbps)
  • Host to HDD Cache speed of 6 Gbps (SATA 2 supports 3 Gbps, SATA 1.5 Gbps)
  • OS/CPU caches further gives better transfer rates
So you can see that if a data transfer (read/write) is done on a NAS and it it hits any cache or disk, then the bottleneck would be the link itself and not the disk I/O operation and the GbE link would become fully saturated practically. 

To get around this, the use of 10 GbE seems logical. But not every device needs such type of transfer speeds. Only NAS and remote workstation. So the best way forward for these very slim minority homes is to either 
  1. Put a small 10 GbE switch and put only NAS and workstation(s) in it and uplink to a slow GbE switch for the rest of the home network devices or even setup P2P 10 GbE links
  2. install 10 GbE NICs (PCI cards)  on both the NAS and the PC (if you have only one) and puit direct P2P ethernet link
  3. If you have multiple clients PCs and one NAS with 100-120 MB/s transfer speed  acceptable, the the switch can be upgraded to a smart 1 gbps switch, A n-port PCI card be put on NAS and link aggregation be used between NAS and switch, leaving the PCs connected to switch with standard 1 Gbps links
So 10 GbE is useful to quickly write small data but lots of it (typical workstation workload) or transfer large files quickly (again largely useful for transferring big video and image files during content creation activities). The "quickly" is the key point or pull for 10 GbE. 

In a nutshell, 10 GbE in home network is an overkill (and still impractical) for 2016 if implemented across the board. Infact most applications ( and most homes) are just fine with 100 mbps (Phone, Tablet, Streamer, Surveillance camera, etc)  with only applications that need to do big file transfer over LAN between two local nodes really needing 1 Gigabit Ethernet.


- Suman Kumar Luthra @ APRC-P3 Telecom Sub-Committee




Saturday 17 October 2015

How to implement a proper conduit design in the home for DC cabling ?

Look closely at this diagram of a tree:

Assume that
  1.  the base of the tree (where the roots and trunk meet) is the STAR point for all sorts of DC cabling (telephone, data, coax)
  2. The leaf is the access point (Rj45, coax or RJ11 socket)
  3. The junction of branch and the trunk is the entry into each room
  4. The junction of the branch and the stem/twig is the link to each access point
Now visualize if the tree was actually a tree of conduits b(pipes) and how much cable each would carry. It should be immediately clear that the trunk carries the max (all cables of the apartment), the branch carries all cables of the room, and the stem/twig carries cables  to a particular access area (like TV, Study, phone stand, etc). So we need to use maximum three type of conduits:

  •  the thinnest from stem-branch junction to each leaf (access point). This can be termed as drop cable.
  • Medium thickness to from trunk-branch junction to a point neat at each wall where you anticipate the need of an access point (typically 2 walls, but could be more)
  • Thickest ones from star point to entry of each room
At each junction, you should use at-least a simple accessible electrical junction box to help routing of the cables. Once these conduits are laid and usable, you can al\ways pull additional cables from star point in future (difficult to anticipate each and every cabling or access point at one go), the only change potentially  required is to pull an additional thin conduit from the wall to that access point. It is also possible to put modular patch panels or junction (very structured wiring) at each junction.

- Suman Kumar Luthra @ APRC-P3 Telecom Sub-Committee

Friday 16 October 2015

Do iI need to ground my switch, router, patch, panel or rack equipment ?

This is an example of how grounding is done for networking gear.


Please take care of the following:

  1. Ensure that the ground wire is not open at any point where you are using a  networking or cable TV equipment. Many surge/extension strips can test this. You should ensure that this is handled in each and every socket in the home to safeguard yourself and equipment. This will ensure that if any static charge is induced in such equipment, it will be discharged immediately
  2. Sometimes, electrostatic charge is induced due to EMI on wires too, especially when they are in close proximity to long runs of AC cable. For LAN cabling the two ends of such cables will be the patch panel and the device itself. As the device is already grounded, you can use a 6 AWG wire to ground the patch panel too. This arrangement will also hold if for some reason you choose to migrate to STP or shielded coax cabling in future. In case your device is 2 pin AC (L-N) but provides a ground terminal, by all means ground the device is similar fashion. Usually equipment with metal chassis will provide a ground terminal on chassis, wehile those using plastic, PVC ort other non-conductive material will not

- Suman Kumar Luthra @ APRC-P3 Telecom Sub-Committee

Thursday 15 October 2015

Are their any safety regulations for AC and DC (coax, telephone, cat6) cabling inside the home ?

There are. Like:

  1. Never run AC and DC cables in same conduit. their is a risk of shorting of DC wires with AC and poses a safety hazard for DC device as well as people who operate them. Plus excessive EMI
  2. You may run these DC cables with AC cables in neighboring conduits (no separation) if both are of made of steel (conduit wall thickness should be atleast 1 mm). If the conduits are ofr aluminium, the conduit wall thickness shoudl be 1.5 mm
  3. If you are using PVC conduits, their should be at-least 5 inches spacing between AC and DC conduits for parallel runs, and the conduits can be intersected crossed at 90 degrees only.
  4. you may run these DC cables with AC cables in neighboring conduits if both are of metal (the steel conduit wall thickness is 1.0 mm while if you use aluminium you have to use 1.5mm thick wall of conduit).


Please refer below standards (Building Codes) from USA for further details (the cables are same quality and hence why should our rules be very different) 

https://drive.google.com/file/d/0B1qwAW9IPZtyakFBYV9CNW9NMkE/view?usp=sharing

- Suman Kumar Luthra @ APRC-P3 Telecom Sub-Committee