mt90226ag ETC-unknow, mt90226ag Datasheet - Page 87

• Manufacturer Part Number: mt90226ag
• Description: 16/8 Port Tc Phy Device
• Manufacturer: ETC-unknow

Data Sheet
11.0
Asynchronous Transfer Mode Adaptation Layer (AAL) - Standardized protocols used to translate higher layer
services from multiple applications into the size and format of an ATM cell. Individual protocols are indexed as per
the examples below:
Active - This is a link state indicating the link is capable of passing ATM Layer cells in the specified direction.
Asynchronous 1. Not synchronous; not periodic.
Asynchronous Transfer Mode (ATM) - A method of organizing information to be transferred into fixed-length cells;
asynchronous in the sense that the recurrence of cells containing information from an individual user is not neces-
sarily periodic.
Cell - Fixed-size information package consisting of 53 bytes (octets) of data; of these, 5 bytes represent the cell
header and 48 bytes carry the user payload and required overhead.
Cell Delay Variation (CDV) - a QoS parameter that measures the peak-to-peak cell delay through the network; re-
sults from buffering and cell scheduling.
Constant Bit Rate - An ATM service category supporting a constant or guaranteed rate, with timing control and
strict performance parameters. Used for services such as voice, video, or circuit emulation.
Header Error Control (HEC) - ATM equipment (usually the PHY) uses the fifth octet in the ATM cell header to check
for an error and correct the contents of the header; CRC algorithm allows for single-error correction and multiple-er-
ror detection.
I.363 - ITU-T Recommendation specifying the AALs for B-ISDN.
Isochronous - The temporal property of an event or signal recurring at known periodic time intervals (e.g. 125 s).
Isochronous signals are dependent on some uniform timing, or carry their own timing information embedded as part
of the signal. Examples are DS-1/T1 and E1. From the root words, “iso” meaning equal, and “chronous” meaning
time.
ITU-T - International Telecommunications Union Telecommunications Standards Sector.
Loss of Cell Delineation (LCD) - The LCD defect is reported when the OCD anomaly persists for the period of time
specified in ITU-T Recommendation I.432(30)¸. The LCD defect is cleared when the OCD anomaly has not been
detected for the period of time specified in ITU-T Recommendation I.432.
Multi-Vendor Integration Protocol (MVIP) - MVIP standards are designed to support the inter-operability of prod-
ucts from different manufacturers and the portability of computer software between products from different manu-
facturers with the goal of facilitating new and improved applications of computer and communications equipment.
AAL0 - Native ATM cell transmission proprietary protocol featuring 5-byte header and 48-byte user pay-
load.
AAL1 - Used for the transport of constant bit rate, time-dependent traffic (e.g. voice, video); requires trans-
fer of timing information between source and destination; maximum of 47-bytes of user data permitted in
payload as an additional header byte is required to provide sequencing information.
AAL5 - Usually used for the transport of variable bit rate, delay-tolerant data traffic and signalling which
requires little sequencing or error-detection support.
Note: Although ATM cells are transmitted synchronously to maintain the clock between sender and receiver, the sender transmits data cells on an as
available basis and transmits empty cells when idle. The sender is not limited to transmitting data every Nth cell.
frequencies and no fixed phase relationship
its occurrence.
ATM Glossary
2. The temporal property of being sourced from independent timing references, having different
3. In telecommunications, data which is not synchronized to the public network clock.
4. The condition or state of being unable to determine exactly when an event will transpire prior to
Zarlink Semiconductor Inc.
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