In the name of Allah,
the Most Gracious, the Most Merciful
By : Lecturer
Telecom. Staff College Haripur.
Digital Cross Connect (DXX)
- Bandwidth Manager.
- DXX node can be described as a digital MUX equipped with several Trunks and Access interfaces.
- Often referred to as a flexible multiplexer or “Flex Mux", reflecting the flexible implementation of different interface connections.
- The DXX can cross-connect any E1 line in the system with any other E1 line in the system
- Provides cross connections from timeslot level to bit level
Slide 5 Slide 6
- Dial Up.
- Local Area Net Work (LAN / WAN).
- Digital Cross Connect (DXX).
- Digital Subscriber Line (xDSL).
- Optical Fiber Access Network (OFAN).
Data Transmission Medias.
- A component in Windows 95 and Windows 98 that enables you to connect your computer to a network via a “modem”.
- If your computer is not connected to a LAN, and you want to connect to the Internet, you need to configure Dial-Up Networking (DUN) to dial a Point of Presence (POP) and log into the Internet Service Provider (ISP). ISP will need to provide certain information, such as the gateway address and your computer's IP address. (Now it is supported automatically)
- You access (DUN) through the My Computer icon. Different profiles (called a connectiod) for different online services can be configured. Once configured, a connectiod shortcut can be copied to a desktop. By double-clicking the connectiod icon, a connection can be established.
- The Integrated Services Digital Network (ISDN) is a set of international standards for access to advanced, all-digital public telecommunications networks. The key elements of this definition are:
- Integrated Services:
- Mixed media at a number of standard
- data rates
- Digital terminal equipment.
- Digital local loops.
- Digital trunks.
- Digital switching.
- Digital signaling.
Worldwide, interoperating communications fabric under distributed control using common standards.
ISDN standards have been defined by the ITU-T , a branch of the United Nations' International Telecommunications Union (ITU), in the series “I” and “Q” recommendations.
- Basic RateAccess (2B+D)
- It contains two Bearer (B) channels 64 Kbps and one signaling channel (D) 16 Kbps.
- So that a total bit rate of 144 Kbps is available on a single twisted copper pair.
- Bearer channels are basically for voice or Data and “D” channel Is for signaling.
- Primary rate Access (30B + D)
- For Broad band services
- It contains thirty Bearer (B) channels 2 Mbps and one signaling channel (D) 64 Kbps.
Key Features of DXX
The DXX provides a complete networking solution to the network operators with the following benefits:
- Efficient utilization of existing transmission bandwidth.
- Powerful NMS to manage large networks.
- The best flexibility for networking.
- Higher service quality and hence higher customer satisfaction.
Key Features of DXX
Super rate :
-Multiplexing of = > 64 K bits / Sec.
-Multiplexing of < 64 K bits / Sec.
Most typical DXX applications are:–
- Data applications.
- Voice applications.
DXX DATA APPLICATIONS
Data Applications include:-
- Leased line data circuits.
- LAN – LAN interconnection.
- Point to Point data.
- Point to multipoint data.
- Paging Systems.
Point to Network
The customer owns or leases the Equipment and subscribes to various Services.
Bridge or Router
Bridge or Router
LAN - LAN Interconnection
Point - Point .
Customer owns or leases the Equipment at all end points. Arranges for the WAN connections from a service provider.
Pont - Multipoint / Super Rate Multiplexing. .
- - Multimedia i.e Video Conference or to Broad casting centre. Banking (ATM), Paging System etc.
- Common Interface speeds for compression 384 Kbps and 768 Kbps.
Paging Control Centre
Paging System .
DXX VOICE APPLICATIONS
Voice Applications include:-
Telephone Line/Number Extension.
Between mobile switching centers.
PSTN – PSTN.
Telephone Line Extension .
Hot Line .
PBX Extension .
P B X
PBX is located at customer site.
DACS Operation .
Digital Access And Cross Connect System acts as a cross over point (Transit Function) for circuits terminating at the end nodes.
DXX APPLICATIONS IN MOBILE
- Analog / Digital mobile traffic between mobile exchanges.
- Voice compression.
- Data traffic.
- LAN interconnection.
- Bandwidth optimization.
DXX Application in Mobile
Advantages of DXX
- Efficient utilization of existing transmission bandwidth/infrastructure.
- Compatible with new emerging standards and future technologies.
- Video conferencing, integrated voice, data management, ISDN, ATM, Frame Relay and SDH back bone network on same platform.
- During a major fault, traffic can be re-routed automatically, so that existing traffic is un-affected
- The operator can also assign various service categories to the customers so that the operator's most valuable business is always protected
- Both of the systems Newbridge & Tellabs have compatibility for frame relay and ATM technology, which is expected to come to Pakistan in near future
Existing DXX Network
In PTCL, presently three systems are being used for the provision of DXX facilities to the subscribers :
1. MARTIS DXX (TELLABS).
2. NEWBRIDGE (MAINSTREET).
3. Loop Telecom.
Planned Expansion in DXX Network
- Cities ----------- 100 to 150 +
- Sites ------------ 200 to 300 +
- Nodes ------------ 205 to 450 +
DXX Systems in Pakistan.
Tellabs/Martiss DXX. 129 Windows NT
Newbridge 131 Solaries O.S.
Loop Telecom. 421 Windows
Cards used in a “DXX” System.
- Media / Back Bone Cards.
- System, Control and Cross Connection cards.
- Line Driving / Access or Subscriber Cards.