JP3591588B2

JP3591588B2 - DSL multiplexer with DSL redundancy switching and program for performing DSL redundancy switching

Info

Publication number: JP3591588B2
Application number: JP2001188557A
Authority: JP
Inventors: 直貴三枝
Original assignee: NEC Corp
Current assignee: NEC Corp
Priority date: 2001-06-21
Filing date: 2001-06-21
Publication date: 2004-11-24
Anticipated expiration: 2021-06-21
Also published as: JP2003008678A

Description

【０００１】
【発明の属する技術分野】
本発明は、ＤＳＬ（ｄｉｇｉｔａｌｓｕｂｓｃｒｉｂｅｒｌｉｎｅ）多重装置に関し、特に、ＤＳＬ冗長切り替え制御技術に関する。
【０００２】
【従来の技術】
ＤＳＬ（ｄｉｇｉｔａｌｓｕｂｓｃｒｉｂｅｒｌｉｎｅ）は、既設の銅線による電話線を利用し、高速データ通信を可能にする手段として導入されている。図６は、ＤＳＬで用いられるＤＳＬ多重装置の概略を示すブロック図であり、局内装置２０と複数の宅内装置２１ａ〜２１ｂからなる。
【０００３】
局内装置２０は、１つのバックボーンと接続されるバックボーンインタフェースと複数のチャネル（以下、ＣＨ）と接続されるＤＳＬインタフェースを有し、多重されたバックボーン信号２２を入力して第１番ＣＨのＤＳＬ信号２３ａ〜第ｎ番ＣＨのＤＳＬ信号２３ｂに分離出力し、また、第１番ＣＨのＤＳＬ信号２３ａ〜第ｎ番ＣＨのＤＳＬ信号２３ｂを入力し、バックボーン信号２２に多重して出力する機能を有している。
【０００４】
第１の宅内装置２１ａ〜第ｎの宅内装置２１ｂは、それぞれ第１番ＣＨのＤＳＬ信号２３ａ〜第ｎ番ＣＨのＤＳＬ信号２３ｂを入力して第１のユーザ信号２４ａ〜第ｎのユーザ信号２４ｂを出力し、また、第１のユーザ信号２４ａ〜第ｎのユーザ２４ｂを入力して第１番ＣＨのＤＳＬ信号２３ａ〜第ｎ番ＣＨのＤＳＬ信号２３ｂを出力する。
【０００５】
このようなＤＳＬ多重装置は、近年、市場に大規模に導入されており、ＤＳＬの収容効率を最大化するように構成されている。また、故障によるサービス断発生時のすみやかなサービス改善をすることが要求されており、そのためにＤＳＬ冗長切り替え機能を備えている。
【０００６】
【発明が解決しようとする課題】
従来のＤＳＬ冗長切り替え付ＤＳＬ多重装置では、故障が発生した場合に冗長ＣＨへの切り替えを手動で行ったり、もしくは、ＤＳＬコアの運用回線を収容しているインタフェース盤の故障に関して自動的に切り替えを行う機能を設けることが考えられている。
【０００７】
しかしながら、冗長ＣＨへの切り替えを手動で行う場合、保守者が障害を検出してから手動で切り替えるまでのサービスの断時間が長くなるという問題があり、また、ＤＳＬコアの運用回線を収容しているインタフェース盤の故障により自動切り替えを行う場合、インタフェース盤の故障検出機能は、ＤＳＬ出力点にもっとも近い点の故障を検出することが困難であるため検出能力が低下する。
【０００８】
また、故障検出機能をＤＳＬコア内に盛り込むことにより故障検出を速やかに行うことも考えられるが、その場合、ＤＳＬコアを構成する集積回路内に故障検出回路を付加する必要があり、ＤＳＬコアの集積度に支障を与える。また故障検出機能が無いものでは、故障検出のトリガがないので自動切り替えができない欠点がある。
【０００９】
本発明の主な目的は、故障検出機能を有していないＤＳＬコアであっても障害検出を可能とする手段を設け、障害発生時に自動切り替えを行うことにより、ＤＳＬのサービス断の時間を最小限に抑えることが可能なＤＳＬ冗長切り替え方法を提供することにある。
【００１０】
【課題を解決するための手段】
本発明は、動作中のＤＳＬコアが出力しているＤＳＬコアの状態遷移を示す信号（状態信号）を監視し、この状態信号からＣＨ毎にＣＨ障害判定を行う手段と、ＣＨ障害が発生したときには、当該ＣＨに接続されているＤＳＬコアを冗長ＣＨに接続されているＤＳＬコアへ自動切り替えする手段を備えたことを特徴とする。
【００１１】
具体的には、ＣＨ毎に接続されたＤＳＬコアから該当ＣＨの起動状態信号を入力し、該当ＣＨ障害判定において障害があると判定された場合で、かつ実装されている冗長ＣＨが未だ使用されていない場合、状態信号から該当ＣＨのＤＳＬパラメータを読み出し、状態信号を介して冗長ＣＨに書き込む。
【００１２】
その後、切り替え信号により該当ＣＨのリレーであるセレクタ（以下、ＳＥＬ）に対して、該当ＣＨの装置内ＤＳＬ信号から冗長ＣＨの装置内ＤＳＬ信号の信号へ選択を切り替える。切り替えた後、状態信号から冗長ＣＨの起動状態を入力し冗長ＣＨの障害判定を行い障害と判定とされない場合、該当ＣＨの故障と判定し、該当ＣＨのクロスコネクト情報を冗長ＣＨのクロスコネクト情報に切り替えるクロスコネクト設定情報をクロスコネクトに設定し、該当ＣＨを冗長運用とする。
【００１３】
また、本発明は、ＣＨの障害を検出した場合で、かつ切り替えた後の冗長ＣＨで同様に障害を検出した場合には、元のチャネルのＤＳＬコアへ自動的に切り戻すことを特徴とする。
【００１４】
具体的には、状態信号から該当ＣＨの起動状態信号を入力し、該当ＣＨ障害判定において障害があると判定された場合で、かつ実装されている冗長ＣＨが未だ使用されていない場合、状態信号から該当ＣＨのＤＳＬパラメータを読み出し、状態信号を介して冗長ＣＨに書き込む。
【００１５】
その後、切り替え信号により該当ＣＨのリレーであるＳＥＬに対して、該当ＣＨの装置内ＤＳＬ信号から冗長ＣＨの装置内ＤＳＬ信号の信号へ選択を切り替える。切り替えた後、状態信号から冗長ＣＨの起動状態を入力し冗長ＣＨの障害判定を行い障害と判定とされた場合、この障害は局内装置内故障以外の故障と判断し、切り替え信号により該当ＣＨのリレーであるＳＥＬに対して、冗長ＣＨの装置内ＤＳＬ信号から該当ＣＨの装置内ＤＳＬ信号の信号へ選択を切り戻し通常運用とする。
【００１６】
また、本発明は、ＣＨの故障をＤＳＬの起動状態を用いて判定することを特徴とする。即ち、ＤＳＬコアの起動失敗が所定回数以上繰り返した場合、あるいは起動指示後所定時間経過しても起動状態とならないときには、ＣＨ障害と判定する。
【００１７】
具体的には、ＣＨのＤＳＬが起動状態でない場合、起動時間タイマ変数ｔ及び起動失敗回数変数ｎを初期化して０とする。初期化後、状態信号から該当ＣＨに対して起動指示を行う。起動指示後、定数時間ｘ後、状態信号から起動状態を読み出す。読み出した結果が起動に成功していない場合、起動失敗回数ｎを１インクリメントする。
【００１８】
インクリメント後起動時間タイマｔが定数Ｔを超えていないことを確認する。確認後、起動失敗回数ｎ変数が定数Ｎを超えていないことを確認する。超えていない場合、再度ＤＳＬ起動指示を行う。この動作を繰り返し、起動失敗回数ｎ変数が定数Ｎとなった場合、ＣＨ障害と判定する。
【００１９】
また、インクリメント後起動時間タイマｔが定数Ｔを超えていないことを確認する。確認後、起動失敗回数ｎ変数が定数Ｎを超えていないことを確認する。超えていない場合、再度ＤＳＬ起動指示を行う。この動作を繰り返し、起動時間ｔ変数が定数Ｔを超えた場合、ＣＨ障害と判定する。
【００２０】
また、本発明は、上記ＤＳＬ冗長切り替え制御を、切り替え制御部内に設けられた処理装置（コンピュータ）に実行させるためのプログラムを備えていることを特徴とする。
【００２１】
【発明の実施の形態】
図６は、本発明が適用されるＤＳＬ冗長切り替え機能付ＤＳＬ多重装置を示しており、局内装置２０と複数の宅内装置２１ａ〜２１ｂからなる。
【００２２】
局内装置２０は、１つのバックボーンインタフェースと複数ＣＨのＤＳＬインタフェースを有しており、バックボーン信号２２を入力して第１番ＣＨのＤＳＬ信号２３ａ〜第ｎ番ＣＨのＤＳＬ信号２３ｂに分離し、複数の第１番ＣＨのＤＳＬ信号２３ａ〜第ｎ番ＣＨのＤＳＬ信号２３ｂを入力してバックボーン信号２２に多重し出力する。
【００２３】
第１の宅内装置２１ａ〜第ｎの宅内装置２１ｂはそれぞれ第１番ＣＨのＤＳＬ信号２３ａ〜第ｎ番ＣＨのＤＳＬ信号２３ｂを入力して第１のユーザ信号２４ａ〜第ｎのユーザ信号２４ｂに出力し、第１のユーザ信号２４ａ〜第ｎのユーザ２４ｂを入力して第１番ＣＨのＤＳＬ信号２３ａ〜第ｎ番ＣＨのＤＳＬ信号２３ｂを出力する。
【００２４】
図１は、本発明の実施形態を示す局内装置のブロック図であり、図６の局内装置２０に対応する。なお、本発明は図６における宅内装置２１ａ〜第ｎの宅内装置２１ｂの構成とは直接関係無いので宅内装置の詳細は省略する。
【００２５】
本発明の局内装置は、ネットワークインタフェース１と、クロスコネクト２と、第１番ＣＨのＤＳＬコア３ａ〜第ｎ番ＣＨのＤＳＬコア３ｂと冗長ＣＨのＤＳＬコア３ｃからなる複数のＤＳＬコアと、第１番ＣＨのＳＥＬ４ａ〜第ｎ番ＣＨのＳＥＬ４ｂからなる複数のＳＥＬと、ＣＨの自動切り替え制御を行う切り替え制御部５からなる。
【００２６】
ネットワークインタフェース１は、多重されたバックボーン信号６を入力し、分離した複数の第１番ＣＨクロスコネクト信号７ａ〜第ｎ番ＣＨクロスコネクト信号７ｂを出力し、複数の第１番ＣＨ局側クロスコネクト信号７ａ〜第ｎ番ＣＨの局側クロスコネクト信号７ｂを入力して多重化し、バックボーン信号６として出力する。バックボーン信号６は、図６のバックボーン信号２２に相当する。
【００２７】
クロスコネクト２は、クロスコネクト設定信号１２を入力し、クロスコネクト設定信号１２で指示される方路設定に従い、第１番ＣＨの局側クロスコネクト信号７ａ〜第ｎ番ＣＨの局側クロスコネクト信号７ｂを入力して第１番ＣＨの加入者側クロスコネクト信号８ａ〜第ｎ番ＣＨの加入者側クロスコネクト信号８ｂと冗長ＣＨの加入者側クロスコネクト信号８ｃを出力し、第１番ＣＨの加入者側クロスコネクト信号８ａ〜第ｎ番ＣＨの加入者側クロスコネクト信号８ｂと冗長ＣＨの加入者側クロスコネクト信号８ｃを入力して第１番ＣＨの局側クロスコネクト信号７ａ〜第ｎ番ＣＨの局側クロスコネクト信号７ｂを出力する。
【００２８】
第１番ＣＨのＤＳＬコア３ａ〜第ｎ番ＣＨのＤＳＬコア３ｂと冗長ＣＨのＤＳＬコア３ｃはそれぞれ、第１番ＣＨの状態信号１３ａ〜第ｎ番ＣＨの状態信号１３ｂと冗長ＣＨの状態信号１３ｃを入力し、第１番ＣＨの状態信号１３ａ〜第ｎ番ＣＨの状態信号１３ｂと冗長ＣＨの状態信号１３ｃから入力されるＤＳＬパラメータと起動指示に従い、第１番ＣＨの加入者側クロスコネクト信号８ａ〜第ｎ番ＣＨの加入者クロスコネクト信号８ｂと冗長ＣＨのクロスコネクト信号８ｃを入力してＤＳＬ信号に変換し、装置内第１番ＣＨのＤＳＬ信号９ａ〜第ｎ番ＣＨのＤＳＬ信号９ｂと冗長ＣＨのＤＳＬ信号９ｃを出力しするとともに、ＤＳＬ信号である第１番ＣＨの装置内ＤＳＬ信号９ａ〜第ｎ番ＣＨの装置内ＤＳＬ信号９ｂと冗長ＣＨの装置内ＤＳＬ信号９ｃを入力して加入者側クロスコネクト信号に変換し、第１番ＣＨの加入者側クロスコネクト信号８ａ〜第ｎ番ＣＨの加入者側クロスコネクト信号８ｂと冗長ＣＨの加入者側クロスコネクト信号８ｃを出力する。
【００２９】
また、第１番ＣＨのＤＳＬコア３ａ〜第ｎ番ＣＨのＤＳＬコア３ｂと冗長ＣＨのＤＳＬコア３ｃはそれぞれ、ＤＳＬの起動状態表示として第１番ＣＨの状態信号１３ａ〜第ｎ番ＣＨの状態信号１３ｂと冗長ＣＨの状態信号１３ｃを出力する。
【００３０】
第１番ＣＨのＳＥＬ４ａ〜第ｎ番ＣＨのＳＥＬ４ｂはそれぞれ、第１番ＣＨの切り替え信号１５ａ〜第ｎ番ＣＨの切り替え信号１５ｂを入力し、第１番ＣＨの切り替え信号１５ａ〜第ｎ番ＣＨの切り替え信号１５ｂで指示される選択指示に従い、第１番ＣＨの装置内ＤＳＬ信号９ａと冗長ＣＨの装置内ＤＳＬ信号９ｃ、第ｎ番ＣＨの装置内ＤＳＬ信号９ｂと冗長ＣＨの装置内ＤＳＬ信号９ｃを入力して第１番ＣＨのＤＳＬ信号１０ａ、第ｎ番ＣＨのＤＳＬ信号１０ｂを出力し、第１番ＣＨのＤＳＬ信号１０ａ、第ｎ番ＣＨのＤＳＬ信号１０ｂを入力して第１番ＣＨの装置内ＤＳＬ信号９ａもしくは冗長ＣＨの装置内ＤＳＬ信号９ｃ、第ｎ番ＣＨの装置内ＤＳＬ信号９ｂもしくは冗長ＣＨの装置内ＤＳＬ信号９ｃを出力する。
【００３１】
第１番ＣＨのＤＳＬ信号１０ａ〜第ｎ番ＣＨのＤＳＬ信号１０ｂはそれぞれ、図６の複数ＣＨのＤＳＬインタフェースである第１番ＣＨのＤＳＬ信号２３ａ〜第ｎ番ＣＨの２３ｂに相当する。
【００３２】
切り替え制御部５は、各ＤＳＬコアからの状態信号１３を入力し、状態信号１３で指示されるＤＳＬの起動状態表示に従い、該当ＣＨのＤＳＬコアと冗長ＣＨのＤＳＬコアが起動状態にあるか否かを判断し、以下の３つの動作を行う。
【００３３】
即ち、状態信号１３で指示される第１番ＣＨのＤＳＬコア３ａ〜第ｎ番ＣＨのＤＳＬコア３ｂにある該当ＣＨのＤＳＬコアのＤＳＬパラメータを入力し、ＣＨ切り替え時に該当ＤＳＬパラメータを冗長ＣＨのＤＳＬコア３ｃへ状態信号１３として出力すること、該当ＣＨのＳＥＬを切り替える指示もしくは切り替え信号１５を出力すること、及び、該当ＣＨと冗長ＣＨ間の方路を入れ替える指示としてクロスコネクト設定信号１２を出力することである。
【００３４】
また状態信号１３は、第１番ＣＨの状態信号１３ａ〜第ｎ番ＣＨの状態信号１３ｂと冗長ＣＨの状態信号１３ｃを示す。切り替え信号１５は、第１番ＣＨの切り替え信号１５ａ〜第ｎ番ＣＨの切り替え信号１５ｂを示す。
【００３５】
図２は、本発明のＣＨ切り替え動作を説明するフローチャートであり、図３は、ＣＨ障害判定動作を説明するフローチャートである。以下、本発明の動作について、図１〜図３を参照して説明する。
【００３６】
切り替え制御部５は、第１番ＣＨのＤＳＬコア３ａ〜第ｎ番ＣＨのＤＳＬコア３ｂからの状態信号１３を監視することにより、ＣＨ毎にＣＨ障害判定を行う（Ｓ１）。
【００３７】
このＣＨ障害判定は、図３に示すように、ＣＨの故障を各ＣＨ毎にＤＳＬの起動状態を監視することにより判定される（Ｓ１１）。
【００３８】
該当ＣＨのＤＳＬが起動状態でない場合（Ｓ１１ＮＯ）、起動時間タイマ変数ｔ及び起動失敗回数変数ｎを初期化して０とする（Ｓ１２）。初期化後、状態信号１３から該当ＣＨに対して起動指示を行う（Ｓ１３）。起動指示から定数時間ｘ後に、状態信号１３から該当ＣＨの起動状態を読み出す（Ｓ１４）ことにより起動したか否かの判定を行う（Ｓ１５）。
【００３９】
読み出した結果が起動に成功していない場合（Ｓ１５ＮＯ）、起動失敗回数ｎを１インクリメントする（Ｓ１６）。インクリメント後、起動時間タイマｔが定数Ｔを超えていないことを確認し（Ｓ１７ＮＯ）、確認後、起動失敗回数ｎ変数が定数Ｎを超えていないことを確認する（Ｓ１８）。
【００４０】
超えていない場合（Ｓ１８ＮＯ）、状態信号１３から再度ＤＳＬ起動指示を行う（Ｓ１３）。この動作を繰り返し、起動失敗回数ｎ変数が定数Ｎと同じになった場合（Ｓ１８ＹＥＳ）、ＣＨ障害と判定する。また、（Ｓ１７）で、起動時間タイマｔが定数Ｔを超えた場合（Ｓ１７ＹＥＳ）も、ＣＨ障害と判定する。
【００４１】
なお、図３では、起動失敗回数ｎと起動時間タイマｔの両方でＣＨ障害判定を行っているが、起動失敗回数ｎのみ、あるいは起動時間タイマｔのみのいずれか一方によりＣＨ障害判定を行うことも可能である。
【００４２】
このようにしてＣＨ障害判定を行った結果、第ｎ番目のＣＨにＣＨ障害が発生しているものとして、次に図２に示すＣＨ切り替え動作を説明する。
【００４３】
状態信号１３から第ｎ番ＣＨの中の起動状態信号を入力し、該当ＣＨ障害判定として第ｎ番ＣＨの障害があると判定された場合、（Ｓ１）のＢが選択される。冗長ＣＨが実装されており（Ｓ２ＹＥＳ）、冗長ＣＨが未だ使用されていない場合（Ｓ３ＮＯ）、状態信号１３から第ｎ番ＣＨのＤＳＬパラメータを読み出し、これを状態信号１３として冗長ＣＨに書き込む（Ｓ４）。
【００４４】
その後、切り替え信号１５により第ｎ番ＣＨのリレーである第ｎ番ＣＨのＳＥＬ４ｂに対して、第ｎ番ＣＨの装置内ＤＳＬ信号９ｂから冗長ＣＨの装置内ＤＳＬ信号９ｃの信号へ選択を切り替える（Ｓ５）。
【００４５】
切り替えた後、状態信号１３から冗長ＣＨの起動状態を入力し冗長ＣＨの障害判定を行い（Ｓ６）、障害と判定されない場合（Ｓ６Ｃ）には、第ｎ番ＣＨの故障と判定し（Ｓ７）、第ｎ番ＣＨのクロスコネクト情報を冗長ＣＨのクロスコネクト情報に切り替える変更をクロスコネクト設定情報１２としてクロスコネクト２に設定を行い（Ｓ８）、冗長運用とする。
【００４６】
また、切り替え信号１５により第ｎ番ＣＨのリレーである第ｎ番ＣＨのＳＥＬ４ｂに対して、第ｎ番ＣＨの装置内ＤＳＬ信号９ｂから冗長ＣＨの装置内ＤＳＬ信号９ｃの信号へ選択を切り替えた（Ｓ５）後、状態信号１３から冗長ＣＨの起動状態を入力し冗長ＣＨの障害判定を行い（Ｓ６）、障害と判定とされた場合（Ｓ６Ｂ）には、第ｎ番ＣＨの障害は局内装置内故障以外の故障によるものと判断し、切り替え信号１５により該当ＣＨのリレーである第ｎ番ＣＨのＳＥＬ４ｂに対して、冗長ＣＨの装置内ＤＳＬ信号９ｃから第ｎ番ＣＨの装置内ＤＳＬ信号９ｂの信号へ選択を切り戻し（Ｓ９）、通常運用とする（Ｓ１０）。
【００４７】
図４及び図５は、本実施形態における通常運用状態の信号の流れと、主信号切り替え動作時の信号の流れを示している。
【００４８】
通常運用状態においては、上り方向の信号の流れは、主信号３０に示されるように第１番ＣＨのＤＳＬ信号１０ａは、リレーで構成される第１番ＣＨのＳＥＬ４ａに入力し選択後、第１番ＣＨの装置内ＤＳＬ信号９ａに出力する。第１番ＣＨの装置内ＤＳＬ信号９ａは、第１番ＣＨのＤＳＬコア３ａに入力しＤＳＬフォーマットから装置内フォーマットに変換された後第１番ＣＨの加入者側クロスコネクト信号８ａに出力される。
【００４９】
第１番ＣＨの加入者側クロスコネクト信号８ａは、クロスコネクト２に入力し方路情報を付加された後第１番ＣＨの局側クロスコネクト信号７ａに出力する。第１番ＣＨの局側クロスコネクト信号７ａは、ネットワークインタフェース１に入力し他の局側クロスコネクト情報と多重してフォーマット変換されバックボーン信号６に出力する。
【００５０】
同様に主信号３１に示されるように第ｎ番ＣＨのＤＳＬ信号１０ｂは、リレーで構成される第ｎ番ＣＨのＳＥＬ４ｂに入力され選択後、第ｎ番ＣＨの装置内ＤＳＬ信号９ｂに出力される。第ｎ番ＣＨの装置内ＤＳＬ信号９ｂは、第ｎ番ＣＨのＤＳＬコア３ｂに入力しＤＳＬフォーマットから置内フォーマットに変換された後第ｎ番ＣＨの加入者側クロスコネクト信号８ｂに出力する。
【００５１】
第ｎ番ＣＨの加入者側クロスコネクト信号８ｂは、クロスコネクト２に入力し方路情報を付加された後第ｎ番ＣＨの局側クロスコネクト信号７ｂに出力される。第ｎ番ＣＨの局側クロスコネクト信号７ｂは、ネットワークインタフェース１に入力し他の局側クロスコネクト情報と多重してフォーマット変換後バックボーン信号６に出力する。
【００５２】
一方、下り方向の流れは、主信号３０に示されるように、バックボーン信号６は、ネットワークインタフェース１に入力し装置内フォーマットに変換されたのち第１番ＣＨの局側クロスコネクト信号７ａに出力する。第１番ＣＨの局側クロスコネクト信号７ａは、クロスコネクト２に入力し方路情報を終端した後、方路情報に従うポートに第１番ＣＨの加入者側クロスコネクト信号８ａを出力する。
【００５３】
第１番ＣＨの加入者側クロスコネクト信号８ａは、第１番ＣＨのＤＳＬコア３ａに入力し装置内フォーマットからＤＳＬフォーマットに変換し第１番ＣＨの装置内ＤＳＬ信号９ａを出力する。第１番ＣＨの装置内ＤＳＬ信号９ａは、リレーで構成される第１番ＣＨのＳＥＬ４ａに入力し第１番ＣＨのＤＳＬ信号１０ａに出力する。
【００５４】
同様に主信号３１に示されるようにバックボーン信号６は、ネットワークインタフェース１に入力し第ｎ番ＣＨの装置内フォーマットに変換されたのち第ｎ番ＣＨの局側クロスコネクト信号７ｂに出力する。第ｎ番ＣＨの局側クロスコネクト信号７ｂは、クロスコネクト２に入力し方路情報を終端した後、方路情報に従うポートに第ｎ番ＣＨの加入者側クロスコネクト信号８ｂを出力する。
【００５５】
第ｎ番ＣＨの加入者側クロスコネクト信号８ｂは、第ｎ番ＣＨのＤＳＬコア３ｂに入力し装置内フォーマットからＤＳＬフォーマットに変換し第ｎ番ＣＨの装置内ＤＳＬ信号９ｂを出力する。第ｎ番ＣＨの装置内ＤＳＬ信号９ｂは、リレーで構成される第ｎ番ＣＨのＳＥＬ４ｂに入力しＤＳＬ信号１０ｂに出力する。
【００５６】
第ｎ番ＣＨに障害が発生し、第ｎ番ＣＨから冗長ＣＨへのＤＳＬラインへの切り替えが行われると、主信号３２の上り信号の流れは、第ｎ番ＣＨのＤＳＬ信号１０ｂは、リレーで構成される第ｎ番ＣＨのＳＥＬ４ｂに入力され選択後、冗長ＣＨの装置内ＤＳＬ信号９ｃに出力される。冗長ＣＨの装置内ＤＳＬ信号９ｃは、冗長ＣＨのＤＳＬコア３ｃに入力しＤＳＬフォーマットから装置内フォーマットに変換された後冗長ＣＨの加入者側クロスコネクト信号８ｃに出力する。
【００５７】
冗長ＣＨのクロスコネクト信号８ｃは、クロスコネクト２に入力し方路情報を付加した後第ｎ番ＣＨの局側クロスコネクト信号７ｂに出力される。第ｎ番ＣＨの局側クロスコネクト信号７ｂは、ネットワークインタフェース１に入力し他の局側クロスコネクト情報と多重してフォーマット変換後バックボーン信号６に出力する。
【００５８】
一方、主信号３２の下り信号の流れは、バックボーン信号６は、ネットワークインタフェース１に入力し装置内フォーマットに変換されたのち第ｎ番ＣＨの局側クロスコネクト信号７ｂに出力する。第ｎ番ＣＨの局側クロスコネクト信号７ｂは、クロスコネクト２に入力し方路情報を終端した後、方路情報に従い冗長ＣＨの加入者側クロスコネクト信号８ｃを出力する。
【００５９】
冗長ＣＨの加入者側クロスコネクト信号８ｃは、冗長ＣＨのＤＳＬコア３ｃに入力し装置内フォーマットからＤＳＬフォーマットに変換し冗長ＣＨの装置内ＤＳＬ信号９ｃを出力する。冗長ＣＨの装置内ＤＳＬ信号９ｃは、リレーで構成される第ｎ番ＣＨのＳＥＬ４ｂに入力し第ｎ番ＣＨのＤＳＬ信号１０ｂに出力する。
【００６０】
図４の主信号３１と図５の主信号３２は、第ｎ番ＣＨのＤＳＬコア３ｂが故障したときに主信号３１から主信号３２に経路を変更することを示している。また第ｎ番ＣＨのＤＳＬコア３ｂを使用するか冗長ＣＨのＤＳＬコア３ｃを使用するかは、局内装置内の経路が異なるのみで、第ｎ番ＣＨのＤＳＬ信号１０ｂとバックボーン信号６の信号は経路変更前と経路変更後で同一であるように動作を行うことで冗長動作となる。
【００６１】
なお、上記実施形態では、冗長ＣＨが１つ設けられている場合について説明したが、故障発生率等を考慮して複数の冗長ＣＨを設けることができることはいうまでもない。
【００６２】
また、本発明におけるＣＨ障害の自動検出及び冗長切り替え動作は、切り替え制御部５内に設けられた処理装置（コンピュータ）に格納されたプログラムにより実行することができる。
【００６３】
【発明の効果】
本発明は、ＣＨの障害を自動的に検出し、自動的に冗長切り替え動作を行っているので、サービス断時間を最少に抑えることができる。
【００６４】
また、切り替えた後のＣＨでの障害を判定する機能を有しているため、局内装置内の障害と局内装置以外の障害を区別することができる。
【００６５】
さらに、動作中のＤＳＬコアから出力される状態信号を監視することにより、実際のＣＨの起動でサービスの障害を確認するため、もっともＤＳＬの出力に近いところの障害まで監視することができ、障害検出能力をあげることができるとともに、ＤＳＬコアに障害検出機能を具備していないＬＳＩ等を使用する場合においても障害の検出が可能となる。
【図面の簡単な説明】
【図１】本発明の実施形態を示すＤＳＬ冗長切り替え付ＤＳＬ多重装置のブロック図である。
【図２】本発明のＣＨ切り替え動作を説明するフローチャートである。
【図３】本発明のＣＨ障害判定動作を説明するフローチャートである。
【図４】本発明のＤＳＬ冗長切り替え付ＤＳＬ多重装置の動作説明図である。
【図５】本発明のＤＳＬ冗長切り替え付ＤＳＬ多重装置の動作説明図である。
【図６】本発明が適用されるＤＳＬ多重装置の概念図である。
【符号の説明】
１ネットワークインタフェース
２クロスコネクト
３ａ第１番ＣＨのＤＳＬコア
３ｂ第ｎ番ＣＨのＤＳＬコア
３ｃ冗長ＣＨのＤＳＬコア
４ａ第１番ＣＨのＳＥＬ
４ｂ第ｎ番ＣＨのＤＳＬコア
５切り替え制御
６バックボーン信号
７ａ第１番ＣＨの局側クロスコネクト信号
７ｂ第ｎ番ＣＨの局側クロスコネクト信号
８ａ第１番ＣＨの加入者側クロスコネクト信号
８ｂ第ｎ番ＣＨの加入者側クロスコネクト信号
８ｃ冗長ＣＨの加入者側クロスコネクト信号
９ａ第１番ＣＨの装置内ＤＳＬ信号
９ｂ第ｎ番ＣＨの装置内ＤＳＬ信号
９ｃ冗長ＣＨの装置内ＤＳＬ信号
１０ａ第１番ＣＨのＤＳＬ信号
１０ｂ第ｎ番ＣＨのＤＳＬ信号
１２クロスコネクト設定信号
１３状態信号
１３ａ第１番ＣＨの状態信号
１３ｂ第ｎ番ＣＨの状態信号
１３ｃ冗長ＣＨの状態信号
１５切り替え信号
１５ａ第１番ＣＨの切り替え信号
１５ｂ第ｎ番ＣＨの切り替え信号
２０局内装置
２１ａ第１の宅内装置
２１ｂ第ｎの宅内装置
２２バックボーン信号
２３ａ第１番ＣＨのＤＳＬ信号
２３ｂ第ｎ番ＣＨのＤＳＬ信号
２４ａ第１のユーザ信号
２４ｂ第ｎのユーザ信号[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a digital subscriber line (DSL) multiplexer, and more particularly to a DSL redundancy switching control technique.
[0002]
[Prior art]
DSL (digital subscriber line) has been introduced as means for enabling high-speed data communication using an existing copper telephone line. FIG. 6 is a block diagram showing an outline of a DSL multiplexing device used in DSL, which comprises an in-station device 20 and a plurality of in-home devices 21a to 21b.
[0003]
The intra-station device 20 has a backbone interface connected to one backbone and a DSL interface connected to a plurality of channels (hereinafter, referred to as CHs), inputs a multiplexed backbone signal 22, and receives a DSL signal of the first CH. It has a function of separating and outputting the DSL signal 23a of the 23rd channel to the n-th channel, and of inputting the DSL signal 23a of the 1st channel to the DSL signal 23b of the nth channel, multiplexing the DSL signal 23b with the backbone signal 22, and outputting it. are doing.
[0004]
The first in-home device 21a to the n-th in-home device 21b receive the DSL signal 23a of the first CH to the DSL signal 23b of the n-th CH, respectively, and receive the first user signal 24a to the n-th user signal 24b. And inputs the first user signal 24a to the nth user 24b to output the DSL signal 23a of the first CH to the DSL signal 23b of the nth CH.
[0005]
Such DSL multiplexing apparatuses have recently been introduced on a large scale in the market, and are configured to maximize the DSL accommodating efficiency. In addition, there is a demand for quick service improvement when a service interruption occurs due to a failure. For this purpose, a DSL redundancy switching function is provided.
[0006]
[Problems to be solved by the invention]
In a conventional DSL multiplexer with DSL redundancy switching, when a failure occurs, switching to a redundant CH is performed manually, or switching is automatically performed for a failure of an interface board accommodating an operation line of a DSL core. It is considered to provide a function to perform.
[0007]
However, when the switching to the redundant CH is performed manually, there is a problem that the service interruption time from the detection of the failure by the maintenance person to the manual switching is long, and the operation line of the DSL core is accommodated. When automatic switching is performed due to a failure of the interface board, the failure detection function of the interface board is difficult to detect a failure at a point closest to the DSL output point, so that the detection capability is reduced.
[0008]
Further, it is conceivable to quickly detect a failure by incorporating a failure detection function in the DSL core. In this case, however, it is necessary to add a failure detection circuit in an integrated circuit constituting the DSL core. It interferes with the degree of integration. In addition, if there is no failure detection function, there is a drawback that automatic switching cannot be performed because there is no trigger for failure detection.
[0009]
A main object of the present invention is to provide a means for detecting a failure even in a DSL core having no failure detection function, and to perform automatic switching when a failure occurs, thereby minimizing a time for a DSL service interruption. It is an object of the present invention to provide a DSL redundancy switching method which can be minimized.
[0010]
[Means for Solving the Problems]
The present invention monitors a signal (state signal) indicating a state transition of a DSL core output from an operating DSL core, performs a CH failure determination for each CH from the state signal, and generates a CH failure. In some cases, a means is provided for automatically switching a DSL core connected to the CH to a DSL core connected to the redundant CH.
[0011]
Specifically, the activation state signal of the relevant CH is input from the DSL core connected for each CH, and when it is determined that there is a failure in the relevant CH failure determination, the mounted redundant CH is still used. If not, the DSL parameter of the corresponding channel is read from the status signal and written to the redundant CH via the status signal.
[0012]
Thereafter, a selector (SEL), which is a relay of the corresponding channel, switches the selection from the in-device DSL signal of the corresponding CH to the in-device DSL signal of the redundant CH by a switching signal. After the switching, the activation state of the redundant CH is input from the status signal, and the failure determination of the redundant CH is performed. If the failure is not determined as a failure, the failure of the corresponding CH is determined, and the cross-connect information of the corresponding CH is replaced with the cross-connect information of the redundant CH. Is set to the cross-connect, and the corresponding CH is set to the redundant operation.
[0013]
Further, the present invention is characterized in that, when a failure of a CH is detected, and when a failure is similarly detected in a redundant CH after switching, switching back to the DSL core of the original channel is automatically performed. .
[0014]
Specifically, when the activation state signal of the relevant CH is input from the state signal, and when it is determined that there is a failure in the relevant CH failure determination, and when the mounted redundant CH is not yet used, the state signal And reads the DSL parameter of the corresponding CH from the corresponding channel, and writes it to the redundant CH via the status signal.
[0015]
Thereafter, the selection signal is switched from the in-device DSL signal of the corresponding CH to the in-device DSL signal of the redundant CH for the SEL which is a relay of the corresponding CH by a switching signal. After the switching, the activation state of the redundant CH is input from the status signal, and the failure determination of the redundant CH is performed. For the SEL that is a relay, the selection is switched back from the in-device DSL signal of the redundant CH to the in-device DSL signal of the corresponding CH, and normal operation is performed.
[0016]
Further, the present invention is characterized in that the failure of the CH is determined using the activation state of the DSL. That is, when the DSL core has failed to start up more than a predetermined number of times, or when the DSL core has not been activated after a lapse of a predetermined time after the start-up instruction, it is determined to be a CH failure.
[0017]
Specifically, when the DSL of the CH is not in the activated state, the activation time timer variable t and the activation failure count variable n are initialized to 0. After the initialization, a start instruction is given to the corresponding CH from the status signal. After the start instruction, after a constant time x, the start state is read from the state signal. If the read result indicates that the activation has not been successful, the activation failure frequency n is incremented by one.
[0018]
After the increment, it is confirmed that the activation time timer t does not exceed the constant T. After the confirmation, it is confirmed that the number n of startup failure times does not exceed the constant N. If not exceeded, a DSL activation instruction is issued again. This operation is repeated, and when the number n of startup failure times becomes a constant N, it is determined that a CH failure has occurred.
[0019]
Further, it is confirmed that the post-increment activation time timer t does not exceed the constant T. After the confirmation, it is confirmed that the number n of startup failure times does not exceed the constant N. If not exceeded, a DSL activation instruction is issued again. This operation is repeated, and if the startup time t variable exceeds the constant T, it is determined that a CH failure has occurred.
[0020]
Further, the present invention is characterized by comprising a program for causing a processing device (computer) provided in a switching control unit to execute the DSL redundancy switching control.
[0021]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 6 shows a DSL multiplexing apparatus with a DSL redundancy switching function to which the present invention is applied, which comprises an intra-office device 20 and a plurality of home devices 21a to 21b.
[0022]
The intra-office device 20 has one backbone interface and a DSL interface of a plurality of channels, receives the backbone signal 22 and separates the backbone signal 22 into a DSL signal 23a of the first CH to a DSL signal 23b of the nth CH. The DSL signal 23a of the first CH to the DSL signal 23b of the nth CH are input, multiplexed with the backbone signal 22, and output.
[0023]
The first in-home device 21a to the n-th in-home device 21b receive the DSL signal 23a of the first CH to the DSL signal 23b of the n-th CH and convert them into the first user signal 24a to the n-th user signal 24b. And outputs the first user signal 24a to the nth user 24b and outputs the DSL signal 23a of the first CH to the DSL signal 23b of the nth CH.
[0024]
FIG. 1 is a block diagram of an intra-station device according to an embodiment of the present invention, and corresponds to the intra-station device 20 of FIG. Note that the present invention has no direct relationship with the configurations of the in-home device 21a to the n-th in-home device 21b in FIG.
[0025]
The intra-station device of the present invention includes a network interface 1, a cross-connect 2, a plurality of DSL cores including a DSL core 3a of the first CH to a DSL core 3b of the n-th CH and a DSL core 3c of the redundant CH. A plurality of SELs including the SEL 4a of the first CH to the SEL 4b of the n-th CH, and a switching control unit 5 for performing automatic switching control of the CH.
[0026]
The network interface 1 receives the multiplexed backbone signal 6, outputs a plurality of separated first CH cross-connect signals 7a to 7th CH cross-connect signals 7b, and outputs a plurality of first CH station-side cross-connects. The signal 7a to the station-side cross-connect signal 7b of the n-th CH are input and multiplexed, and output as a backbone signal 6. The backbone signal 6 corresponds to the backbone signal 22 in FIG.
[0027]
The cross-connect 2 receives the cross-connect setting signal 12 and, in accordance with the route setting indicated by the cross-connect setting signal 12, the first channel station-side cross-connect signal 7a to the n-th channel station-side cross-connect signal. 7b, and outputs a subscriber cross-connect signal 8a of the first CH to a subscriber cross-connect signal 8b of the n-th CH and a subscriber cross-connect signal 8c of the redundant CH. The subscriber-side cross-connect signal 8a to the n-th CH subscriber-side cross-connect signal 8b and the redundant CH subscriber-side cross-connect signal 8c are input to the first CH for the station-side cross-connect signal 7a to n-th. It outputs the station-side cross-connect signal 7b of the CH.
[0028]
The DSL core 3a of the first CH to the DSL core 3b of the nth CH and the DSL core 3c of the redundant CH are respectively the first CH status signal 13a to the nth CH status signal 13b and the redundant CH status signal. 13c, and in accordance with DSL parameters and start-up instructions input from the status signal 13a of the first CH to the status signal 13b of the nth CH and the status signal 13c of the redundant CH, the subscriber-side cross-connect of the first CH Signals 8a to n-th CH subscriber cross-connect signal 8b and redundant CH cross-connect signal 8c are input and converted to DSL signals, and DSL signals 9a to 9th to DSL signals for the first CH in the device. 9b and the DSL signal 9c of the redundant CH, and outputs the DSL signal 9a to the DSL signal 9a to the nth CH and the DSL signal 9b of the redundant CH. The SL signal 9c is input and converted into a subscriber-side cross-connect signal. The subscriber-side cross-connect signal 8a of the first CH and the subscriber-side cross-connect signal 8b of the n-th CH and the subscriber cross of the redundant CH are converted. It outputs a connect signal 8c.
[0029]
In addition, the DSL core 3a of the first CH to the DSL core 3b of the nth CH and the DSL core 3c of the redundant CH respectively indicate the status signal 13a to the nth CH of the first CH as the DSL activation status display. The signal 13b and the state signal 13c of the redundant CH are output.
[0030]
The SEL4a of the first CH to the SEL4b of the nth CH receive the first CH switching signal 15a to the nth CH switching signal 15b, respectively, and the first CH switching signal 15a to the nth CH In accordance with the selection instruction indicated by the switching signal 15b, the internal DSL signal 9a of the first CH and the internal DSL signal 9c of the redundant CH, the internal DSL signal 9b of the nth CH, and the internal DSL signal of the redundant CH 9c and outputs the DSL signal 10a of the first CH and the DSL signal 10b of the nth CH. The DSL signal 10a of the first CH and the DSL signal 10b of the nth CH are input and the first DSL signal 10b. The internal DSL signal 9a of the CH, the internal DSL signal 9c of the redundant CH, the internal DSL signal 9b of the nth CH, or the internal DSL signal 9c of the redundant CH are output.
[0031]
The DSL signals 10a of the first CH to the DSL signals 10b of the nth CH correspond to the DSL signals 23a of the first CH to 23b of the nth CH, respectively, which are the DSL interfaces of a plurality of CHs in FIG.
[0032]
The switching control unit 5 receives the status signal 13 from each DSL core, and determines whether the DSL core of the corresponding channel and the DSL core of the redundant channel are in the active status according to the activation status display of the DSL indicated by the status signal 13. And the following three operations are performed.
[0033]
That is, the DSL parameters of the DSL core of the corresponding CH in the DSL core 3a of the first CH to the DSL core 3b of the nth CH indicated by the status signal 13 are input, and the corresponding DSL parameter is changed to the redundant CH at the time of CH switching. A cross-connect setting signal 12 is output to the DSL core 3c as a status signal 13, an instruction to switch the SEL of the corresponding CH or an output of the switching signal 15, and an instruction to switch the route between the corresponding CH and the redundant CH. It is to be.
[0034]
The status signal 13 indicates a status signal 13a of the first CH to a status signal 13b of the nth CH and a status signal 13c of the redundant CH. The switching signal 15 indicates a switching signal 15a for the first CH to a switching signal 15b for the nth CH.
[0035]
FIG. 2 is a flowchart illustrating the CH switching operation of the present invention, and FIG. 3 is a flowchart illustrating the CH failure determination operation. Hereinafter, the operation of the present invention will be described with reference to FIGS.
[0036]
The switching control unit 5 performs the CH failure determination for each CH by monitoring the status signals 13 from the DSL core 3a of the first CH to the DSL core 3b of the nth CH (S1).
[0037]
As shown in FIG. 3, this CH failure determination is made by monitoring the activation state of the DSL for each CH for the failure of the CH (S11).
[0038]
If the DSL of the corresponding CH is not in the activated state (S11 NO), the activation time timer variable t and the activation failure frequency variable n are initialized to 0 (S12). After the initialization, a start instruction is issued from the state signal 13 to the corresponding CH (S13). After a constant time x from the activation instruction, the activation state of the corresponding CH is read from the status signal 13 (S14) to determine whether or not the CH has been activated (S15).
[0039]
If the read result indicates that the activation has not been successful (NO in S15), the activation failure frequency n is incremented by 1 (S16). After the increment, it is confirmed that the activation time timer t does not exceed the constant T (S17 NO), and after the confirmation, it is confirmed that the activation failure frequency n variable does not exceed the constant N (S18).
[0040]
If not exceeded (S18 NO), a DSL activation instruction is issued again from the state signal 13 (S13). This operation is repeated, and when the number n of startup failure times becomes equal to the constant N (S18 YES), it is determined that a CH failure has occurred. Also, in (S17), if the activation time timer t exceeds the constant T (S17 YES), it is determined that a CH failure has occurred.
[0041]
In FIG. 3, the CH failure determination is performed using both the activation failure count n and the activation time timer t. However, the CH failure determination is performed based on either the activation failure count n alone or the activation time timer t alone. Is also possible.
[0042]
Assuming that a CH failure has occurred in the n-th CH as a result of performing the CH failure determination in this manner, the CH switching operation shown in FIG. 2 will be described next.
[0043]
When an activation state signal in the n-th CH is input from the state signal 13 and it is determined that there is a failure in the n-th CH as the relevant CH failure determination, B in (S1) is selected. If the redundant CH is mounted (S2 YES) and the redundant CH is not yet used (S3 NO), the DSL parameter of the n-th CH is read from the state signal 13 and written to the redundant CH as the state signal 13 (S4). ).
[0044]
Thereafter, the selection signal is switched from the in-device DSL signal 9b of the nth CH to the in-device DSL signal 9c of the redundant CH for the nth CH SEL 4b, which is the nth CH relay, by the switching signal 15 ( S5).
[0045]
After the switching, the activation state of the redundant CH is input from the state signal 13 to determine the failure of the redundant CH (S6). If the failure is not determined (S6C), it is determined to be the failure of the nth CH (S7). The change to switch the cross-connect information of the n-th CH to the cross-connect information of the redundant CH is set in the cross-connect 2 as the cross-connect setting information 12 (S8), and the redundant operation is performed.
[0046]
Further, the selection signal is switched from the in-device DSL signal 9b of the nth CH to the in-device DSL signal 9c of the redundant CH for the nth CH SEL 4b, which is the nth CH relay, by the switching signal 15. (S5) After that, the activation state of the redundant CH is input from the status signal 13 to determine the failure of the redundant CH (S6). If it is determined that the failure has occurred (S6B), the failure of the n-th CH is determined by the in-station device. It is determined that the failure is caused by a failure other than the internal failure, and the switching signal 15 is used to switch the SEL signal 4b of the nth CH, which is the relay of the corresponding CH, from the DSL signal 9c of the redundant CH to the DSL signal 9b of the nth CH The selection is switched back to the signal (S9), and normal operation is performed (S10).
[0047]
4 and 5 show a signal flow in the normal operation state and a signal flow at the time of the main signal switching operation in the present embodiment.
[0048]
In the normal operation state, as shown in the main signal 30, the upstream signal flow is such that the DSL signal 10a of the first CH is input to the SEL 4a of the first CH constituted by a relay, and is selected. This is output as the in-device DSL signal 9a of the first CH. The in-device DSL signal 9a of the first CH is input to the DSL core 3a of the first CH, converted from the DSL format to the in-device format, and then output as the subscriber cross-connect signal 8a of the first CH. .
[0049]
The first channel subscriber-side cross-connect signal 8a is input to the cross-connect 2, added with route information, and then output as the first channel station-side cross-connect signal 7a. The station-side cross-connect signal 7a of the first CH is input to the network interface 1, multiplexed with other station-side cross-connect information, format-converted, and output as the backbone signal 6.
[0050]
Similarly, as shown in the main signal 31, the n-th CH DSL signal 10b is input to the n-th CH SEL 4b formed by a relay, selected, and then output as the n-th CH internal DSL signal 9b. You. The in-device DSL signal 9b of the n-th CH is input to the DSL core 3b of the n-th CH, converted from the DSL format into the in-house format, and then output as the subscriber cross-connect signal 8b of the n-th CH.
[0051]
The subscriber-side cross-connect signal 8b of the n-th CH is input to the cross-connect 2, added with the route information, and output as the station-side cross-connect signal 7b of the n-th CH. The station-side cross-connect signal 7b of the n-th CH is input to the network interface 1, multiplexed with other station-side cross-connect information, and output as a backbone signal 6 after format conversion.
[0052]
On the other hand, in the downstream flow, as shown by the main signal 30, the backbone signal 6 is input to the network interface 1 and converted into the in-apparatus format, and then output as the first channel station-side cross-connect signal 7a. . The first channel station-side cross-connect signal 7a is input to the cross-connect 2, terminates the route information, and then outputs the first channel subscriber-side cross-connect signal 8a to a port according to the route information.
[0053]
The subscriber CH cross-connect signal 8a of the first CH is input to the DSL core 3a of the first CH, converted from the in-device format to the DSL format, and outputs the in-device DSL signal 9a of the first CH. The in-device DSL signal 9a of the first CH is input to the SEL 4a of the first CH constituted by a relay and output as the DSL signal 10a of the first CH.
[0054]
Similarly, as shown in the main signal 31, the backbone signal 6 is input to the network interface 1, converted into the n-th CH internal format, and then output as the n-th CH station-side cross-connect signal 7b. The station-side cross-connect signal 7b of the n-th CH is input to the cross-connect 2, terminates the route information, and then outputs a subscriber-side cross-connect signal 8b of the n-th CH to a port according to the route information.
[0055]
The subscriber cross-connect signal 8b of the n-th CH is input to the DSL core 3b of the n-th CH, converted from the in-device format to the DSL format, and outputs the in-device DSL signal 9b of the n-th CH. The in-device DSL signal 9b of the n-th CH is input to the SEL 4b of the n-th CH constituted by a relay and output as a DSL signal 10b.
[0056]
When a failure occurs in the nth CH and switching to the DSL line from the nth CH to the redundant CH is performed, the flow of the upstream signal of the main signal 32 is such that the DSL signal 10b of the nth CH is Is input to the SEL 4b of the n-th CH, and is selected and output as the in-device DSL signal 9c of the redundant CH. The in-device DSL signal 9c of the redundant CH is input to the DSL core 3c of the redundant CH, converted from the DSL format into the in-device format, and then output as the subscriber cross-connect signal 8c of the redundant CH.
[0057]
The redundant CH cross-connect signal 8c is input to the cross-connect 2, adds route information, and is output as the n-th CH station-side cross-connect signal 7b. The station-side cross-connect signal 7b of the n-th CH is input to the network interface 1, multiplexed with other station-side cross-connect information, and output as a backbone signal 6 after format conversion.
[0058]
On the other hand, as for the downstream signal flow of the main signal 32, the backbone signal 6 is input to the network interface 1 and converted into the in-apparatus format, and then is output as the n-th CH station-side cross-connect signal 7b. The station-side cross-connect signal 7b of the n-th CH is input to the cross-connect 2, terminates the route information, and then outputs the redundant CH subscriber-side cross-connect signal 8c according to the route information.
[0059]
The subscriber side cross-connect signal 8c of the redundant CH is input to the DSL core 3c of the redundant CH, converted from the internal format to the DSL format, and outputs the internal DSL signal 9c of the redundant CH. The in-device DSL signal 9c of the redundant CH is input to the SEL 4b of the n-th CH configured as a relay and output as the DSL signal 10b of the n-th CH.
[0060]
The main signal 31 in FIG. 4 and the main signal 32 in FIG. 5 indicate that the path is changed from the main signal 31 to the main signal 32 when the DSL core 3b of the n-th CH fails. Whether the DSL core 3b of the nth CH or the DSL core 3c of the redundant CH is used is only a different route in the intra-office device, and the DSL signal 10b of the nth CH and the signal of the backbone signal 6 are different. The redundant operation is performed by performing the same operation before the route change and after the route change.
[0061]
In the above embodiment, the case where one redundant CH is provided has been described, but it goes without saying that a plurality of redundant CHs can be provided in consideration of the failure occurrence rate and the like.
[0062]
Further, the automatic detection of the CH failure and the redundant switching operation in the present invention can be executed by a program stored in a processing device (computer) provided in the switching control unit 5.
[0063]
【The invention's effect】
According to the present invention, the failure of the CH is automatically detected and the redundancy switching operation is automatically performed, so that the service interruption time can be minimized.
[0064]
In addition, since it has a function of determining a failure in the CH after switching, it is possible to distinguish between a failure in the intra-station device and a failure other than the intra-station device.
[0065]
Further, by monitoring the status signal output from the operating DSL core, it is possible to check the failure of the service at the actual activation of the CH. Therefore, it is possible to monitor even the failure closest to the DSL output. The detection capability can be improved, and the failure can be detected even when using an LSI or the like which does not have a failure detection function in the DSL core.
[Brief description of the drawings]
FIG. 1 is a block diagram of a DSL multiplexer with DSL redundancy switching showing an embodiment of the present invention.
FIG. 2 is a flowchart illustrating a CH switching operation of the present invention.
FIG. 3 is a flowchart illustrating a CH failure determination operation according to the present invention.
FIG. 4 is a diagram illustrating the operation of the DSL multiplexer with DSL redundancy switching of the present invention.
FIG. 5 is a diagram illustrating the operation of the DSL multiplexer with DSL redundancy switching according to the present invention.
FIG. 6 is a conceptual diagram of a DSL multiplexer to which the present invention is applied.
[Explanation of symbols]
Reference Signs List 1 network interface 2 cross-connect 3a DSL core 3b of 1st CH DSL core 3c of nth CH DSL core 4a of redundant CH 4th SEL of 1st CH
4b DSL core 5 of n-th CH 5 Switching control 6 backbone signal 7a station-side cross-connect signal 7b of first channel 7b station-side cross-connect signal 8a of n-th channel Subscriber-side cross-connect signal 8b of first CH Subscriber-side cross-connect signal 8c for n-th channel Subscriber-side cross-connect signal 9a for redundant CH 9th in-device DSL signal 9b for 1st CH 9th in-device DSL signal 9c for nth CH In-device DSL signal 10a for redundant CH 1st CH DSL signal 10b nth CH DSL signal 12 cross-connect setting signal 13 status signal 13a 1st CH status signal 13b nth CH status signal 13c redundant CH status signal 15 switching signal 15a 1st CH-number switching signal 15b n-th CH switching signal 20 In-station device 21a First in-home device 21b n-th in-home device 2 Backbone signal 23a DSL signal 24a first user signal 24b user signal of the n of the DSL signal 23b n-th CH of No. 1 CH

Claims

It has a backbone interface connected to one backbone and a DSL interface connected to a plurality of home devices, receives a multiplexed backbone signal, separates and outputs the DSL signal of a plurality of channels, and outputs a DSL signal of a plurality of channels. In the DSL multiplexer with DSL redundancy switching having a function of inputting, multiplexing and outputting as a backbone signal,
Means for monitoring a state signal indicating a state transition of the DSL core output from the operating DSL core and performing a CH failure determination for each CH based on the state signal; Means for switching the connected DSL core to the DSL core connected to the redundant CH ,
The CH failure determination means includes: a means for detecting an activation state of the DSL core for each CH; a means for initializing an activation time timer when a DSL core that is not in an activation state is detected; Means for instructing the activation of the corresponding channel by a status signal, means for determining the activation state of the corresponding channel after a predetermined time from the activation instruction, and the timer is set to a predetermined time when the activation fails as a result of the determination. A means for repeating the start instruction on condition that the time does not exceed, and a means for performing a CH failure determination when the timer exceeds the set time during the repetition of the start instruction. DSL multiplexer with DSL redundancy switching.

It has a backbone interface connected to one backbone and a DSL interface connected to a plurality of home devices, receives a multiplexed backbone signal, separates and outputs the DSL signal of a plurality of channels, and outputs a DSL signal of a plurality of channels. In the DSL multiplexer with DSL redundancy switching having a function of inputting, multiplexing and outputting as a backbone signal,
Means for monitoring a state signal indicating a state transition of the DSL core output from the operating DSL core and performing a CH failure determination for each CH based on the state signal; Means for switching the connected DSL core to the DSL core connected to the redundant CH,
The CH failure determination means includes means for detecting an activation state of the DSL core for each CH, means for initializing the number of activation failures when a DSL core not in the activation state is detected, and after the initialization, Means for issuing an activation instruction to the corresponding CH by a status signal, means for determining the activation state of the relevant CH after a predetermined time from the activation instruction, and when the activation fails as a result of the determination, the activation failure count is incremented by one. Means for repeating the start instruction on condition that the number of startup failures is smaller than a preset number of times, and a CH failure when the number of startup failures matches the set number of times while the startup instruction is repeated. A DSL multiplexer with DSL redundancy switching, comprising: means for making a determination .

It has a backbone interface connected to one backbone and a DSL interface connected to a plurality of home devices, receives a multiplexed backbone signal, separates and outputs the DSL signal of a plurality of channels, and outputs a DSL signal of a plurality of channels. In the DSL multiplexer with DSL redundancy switching having a function of inputting, multiplexing and outputting as a backbone signal,
Means for monitoring a state signal indicating a state transition of the DSL core output from the operating DSL core and performing a CH failure determination for each CH based on the state signal; Means for switching the connected DSL core to the DSL core connected to the redundant CH,
The CH failure determination means includes: a means for detecting an activation state of the DSL core for each CH; a means for initializing a startup time timer and the number of startup failures when a DSL core not in the activation state is detected; Means for instructing the CH to be activated by the status signal after the initialization, means for deciding the activation state of the CH after a predetermined time from the activation instruction, and the activation failure count when the activation fails as a result of the determination. Means for repeating the start instruction on condition that the timer does not exceed a preset time and that the number of failed start-ups is less than a preset number; and Perform a CH failure determination when the timer exceeds the set time or when the number of startup failures matches the set number of times. DSL multiplexing device with DSL redundancy switching, characterized in that it comprises a stage.

4. The system according to claim 1, further comprising: means for determining a failure of the redundant CH after the switching, and means for switching back to the original CH when a CH failure occurs in the redundant CH. A DSL multiplexing apparatus with DSL redundancy switching according to any of the above items.

It has a backbone interface connected to one backbone and a DSL interface connected to a plurality of home devices, receives a multiplexed backbone signal, separates and outputs the DSL signal of a plurality of channels, and outputs a DSL signal of a plurality of channels. And a computer for executing DSL redundancy switching processing in a DSL multiplexing apparatus with DSL redundancy switching that inputs and multiplexes the signals as a backbone signal,
Monitoring the state signal indicating the state transition of the DSL core output by the operating DSL core to determine a CH failure for each CH from the state signal; Switching the connected DSL core to the DSL core connected to the redundant CH,
The step of performing the CH failure determination includes a step of detecting a startup state of the DSL core for each CH, a step of initializing a startup time timer when a DSL core that is not in the startup state is detected, and after the initialization. A step of giving a start instruction to the corresponding CH by the state signal, a step of determining the start state of the relevant CH after a lapse of a predetermined time from the start instruction, and the step of setting the timer when the start fails as a result of the determination. A step of repeating the start instruction on condition that the time does not exceed, and a step of determining a CH failure when the timer exceeds the set time during repetition of the start instruction. Features program.

It has a backbone interface connected to one backbone and a DSL interface connected to a plurality of home devices, receives a multiplexed backbone signal, separates and outputs the DSL signal of a plurality of channels, and outputs a DSL signal of a plurality of channels. And a computer for executing a DSL redundancy switching process in the DSL multiplexing apparatus with DSL redundancy switching that inputs and multiplexes and outputs as a backbone signal,
Performing a CH fault determination for each CH from the status signal by monitoring a status signal indicating a status transition of the DSL core output by the operating DSL core; Switching the connected DSL core to the DSL core connected to the redundant CH ,
The step of performing the CH failure determination includes a step of detecting the activation state of the DSL core for each CH, a step of initializing the number of activation failures when a DSL core that is not in the activation state is detected, and Issuing a start instruction to the corresponding CH by the state signal; determining a start state of the corresponding CH after a lapse of a predetermined time from the start instruction; and incrementing the start failure count by 1 when the start fails as a result of the determination. Repeating the activation instruction on condition that the number of times of activation failures is less than a preset number of times. When the number of times of activation failures coincides with the set number of times during the repetition of the activation instructions, CH A program comprising a step of determining a failure .

It has a backbone interface connected to one backbone and a DSL interface connected to a plurality of home devices, receives a multiplexed backbone signal, separates and outputs the DSL signal of a plurality of channels, and outputs a DSL signal of a plurality of channels. And a computer for executing a DSL redundancy switching process in the DSL multiplexing apparatus with DSL redundancy switching that inputs and multiplexes and outputs as a backbone signal,
Performing a CH fault determination for each CH from the status signal by monitoring a status signal indicating a status transition of the DSL core output by the operating DSL core; Switching the connected DSL core to the DSL core connected to the redundant CH,
The step of performing the CH failure determination includes a step of detecting a startup state of the DSL core for each CH; and a step of initializing a startup time timer and a startup failure count when a DSL core that is not in an activation state is detected. Performing a start instruction for the corresponding CH by the state signal after the initialization; determining a start state of the corresponding CH after a predetermined time from the start instruction; Repeating the start instruction on the condition that the number of times is incremented by one and that the timer does not exceed a preset time and that the start failure count is less than a preset count; and During the time when the timer exceeds the set time or when the number of startup failures matches the set number of times Program characterized by comprising: determining a CH fault can.

After executing the step of switching the DSL core to a DSL core connected to a redundant CH, performing a failure determination of the redundant CH, and switching back to the original CH when a CH failure occurs in the redundant CH. The program according to any one of claims 5 to 7, further comprising a performing step .