RJ -45 (Registered Jack -45)

RJ45 is a standard type of connector for network cables. RJ45 connectors are most commonly seen with Ethernet cables and networks.

RJ45 connectors feature eight pins to which the wire strands of a cable interface electrically. Standard RJ-45 pinouts define the arrangement of the individual wires needed when attaching connectors to a cable.

Several other kinds of connectors closely resemble RJ45 and can be easily confused for each other. The RJ-11 connectors used with telephone cables, for example, are only slightly smaller (narrower) than RJ-45 connectors.

OSI model

Partitioning the whole network structures into the abstract layers ISO established a 7 layered architecture named as :-------

7. Application  Network process to application
6. Presentation Data representation, encryption and decryption, convert machine dependent data to machine independent data
5. Session -    Interhost communication, managing sessions between applications
4. Transport     Reliable delivery of packets between points on a network.
3. Network     Addressing, routing and (not necessarily reliable) delivery of datagrams between points on a network.
2. Data link     A reliable direct point-to-point data connection.
1. Physical     A (not necessarily reliable) direct point-to-point data connection.

Confusions to confuse you???

>>The Session Initiation Protocol (SIP) is a protocol related to which layer??
 A) Session
B) Application

Answer -- Application

What is RS in RS-232 ?

RS-232 is defined as the. “Interface between data terminal equipment and data communications equipment using serial binary data exchange.

RS-232 (Recommended Standard - 232) is a telecommunications standard for binary serial communications between devices.

Global Title vs. Point Code

GT AND SPC are using for addressing and routing of the message in SS7 network. But GT is only used for routing messages at SCCP level. GT is formated as national number.


In simple terms Global Title is used at SCCP level in a SS7 stack and Point code is used at MTP level.
GT is an unique identity of a Network Element while Point code is unique with in a particular SS7 network.
lets say for example : there are two Telecom operators Airtel, Idea . no two GT will be same in these two networks but we can have same Point codes in both networks.

Signalling System No. 7

Signalling System No. 7 (SS7)

> Not  a single protocol but a set of  telephony signaling protocols which are being used to set up telephone calls.

>The main purpose is to set up and tear down telephone calls.

>Other uses include number translation, local number portability, prepaid billing mechanisms, short message service (SMS), and a variety of other mass market services.

Validity period of an SMS message

An SMS message is stored temporarily in the SMS center if the recipient mobile phone is unavailable. It is possible on most mobile handset to specify an expiry period after which the SMS message will be deleted from the SMS center. Once deleted, the SMS message will no longer be available for dispatch to the recipient mobile phone (even if it becomes online). The validity period should be regarded by the handset user as a request, as the SMSC itself can be configured to ignore or otherwise handle message delivery schedules.

Short message service center(SMSC)

A short message service center (SMSC) is a network element in the mobile telephone network. Its purpose is to store, forward, convert and deliver SMS messages.
The full designation of an SMSC according to 3GPP is Short Message Service - Service Centre (SMS-SC)
Basic Trajectories of SMS are

1. From Mobile to another Mobile, this trajectory is referred as MO-MT (Mobile Originated - Mobile Terminated)
2. From Mobile to a content provider (also called as Large Account / ESME), this trajectory is referred as MO-AT (Mobile Originated - Application Terminated)
3. From Application to a Mobile, this trajectory is referred as AO-MT (Application Originated - Mobile Terminated)

An SMS center (SMSC) is responsible for handling the SMS operations of a wireless network.

1. When an SMS message is sent from a mobile phone, it will reach an SMS center first.
2. The SMS center then forwards the SMS message towards the destination.
3. The main duty of an SMSC is to route SMS messages and regulate the process. If the recipient is unavailable (for example, when the mobile phone is switched off), the SMSC will store the SMS message.
4. It will forward the SMS message when the recipient is available or when the message's expiry period is exceeded.