The System Description and Functional Aspects of
Ranks ITT Network
Ranks ITT Ltd. is a Network
Communication Service Provider and first of its
kind in Bangladesh in the private sector. The
company has developed a hybrid network comprising
fiber, wireless and xDSL equipment for last mile
as well as for backbone solution in order to
provide end-to-end services for the valued
clients. For long distance communication i.e. for
inter region communication within the country, the
company is utilizing the fiber optic backbone (SDH
optical network) outsourced from Bangladesh
Railway. Bangladesh Railway has been using this
network for the last 8-9 years for its own
purpose; later on Grameenphone, a subsidiary of
TELENOR, took lease of the excess capacity of the
bandwidth for 20 years and eventually got
permission to sublease it. The network was
subsequently upgraded from PDH to SDH standard.
Initially it was having STM-1 (155Mbps) capacity
and now part of it has been upgraded to STM-4
(622Mbps) and STM-16. Out of this network
capacity, Grameen is providing N x E1 circuits to
its sub lessees for carrying data/IP
voice/streaming video traffic over long distances.
Basically, the network is providing a transparent TDM carrier for transporting the aforementioned Net traffic. Different protocols and WAN services can be utilized to ensure QoS. CoS, CIR/MIR etc. There fore, different WAN protocols like IP, Frame Relay, X.25 etc. or combination of protocols for UNI and NNI can be applied for the purpose. Right at this moment based on the existing setup, Ranks ITT has been providing three types of WAN services for the clients: 1)
End-to-end N x 64K
transparent TDM channels for corporate clients who
are asking for protocol independent clear channels
for their communication purpose and they will use
serial (V.35) routers to ensure efficient routing,
QoS, traffic management etc.
2)
End-to-end N x 64K
dedicated Ethernet/IP based (IP over TDM) transit
path for the clients who are asking for dedicated
IP transit path for interconnecting their
different branch offices and they want to use
their own IP addresses and router to ensure
privacy, security, efficient routing, traffic
management, QoS etc. Basically what they want is
to have a transparent bridged path from Ranks ITT.
This transit path is certainly not a shared data
path, it is a dedicated one.
3)
Shared / Burst IP
based data path for non-critical clients who are
not that much quality and security conscious and
are rather cost conscious. We induce them to have
small IP routers to avoid congestions and to
ensure privacy for their network.
Currently we are not
having any packet switched WAN service for data
communication. But eventually we are planning to
establish a core IP network running over a MPLS
backbone supporting a true carrier class
multiservice network. According to the current
network design, the system will act only as a
transparent carrier for the data passing through
it. At the Drop-Insert points, Digital Cross
Connects and E1 Access Multiplexers are used to
fractionalize the data channels and IP/TDM/Serial
communication based radio equipments and/or xDSL
systems are used to provide last mile solution.
The
Access multiplexers facilitate fractionalization
of E1 trunks and the maintenance of the committed
Data Rate. The mux is also acting as an interface
converter for the last mile solution as it houses
several I/O modules having multiple V.35 or
Ethernet 10 Base T ports. The module with Ethernet
data port can map N x 64K channels over IP path
and can channel the traffic on designated ports.
This module also supports 802.1q VLAN tagging.
Therefore, channels configured for one specific
client mapped to a designated Ethernet port in an
I/O module will never get mixed with channels
configured for another client mapped to another
Ethernet port of the same I/O module. Last mile
radios or DSL modem connections are extended from
these I/O modules in order to connect the CPE
unit. This feature ensures a level of security for
the data path used by a client. The multiplexer
can also help in managing the network activities,
performances and loop testing |
